Homework

1. Laboratory 3: Electrical circuits - Basic

When using the voltmeter to measure the voltage across a component in

circuit, you must connect it in parallel with that component. To measure

current with the ammeter marked in the figure, then connect it in series in the circuit.

The ammeter is thus part of the circuit and the current passes through

ammeter.

Tasks

1. Circuit with lamps

a) Connect a lamp (10 ohms) to a power source (9 V) according to

wiring diagram A.

Create another circuit on the same table with two lamps (10 ohms each) and

a power source according to wiring diagram B.

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Which of the circuits A or B should emit the most light?

RESPONSE:

b) By connecting in parallel across the voltage source as in the wiring diagram

C you can study the lights at the same time. Compare how strong the lights are

1,2 and 3 are lit. Is there a lamp that shines brightest or weakest?

RESPONSE:

5

2. Serial connection of batteries

A so-called AA battery, see picture, is a regular household battery.

What is the normal voltage of such a battery? Search the internet

if you feel insecure.

RESPONSE:

If you connect three AA batteries in series as a power source, which

pole voltage gets the power source?

RESPONSE:

Connect three AA batteries (power sources with appropriate selection

voltage) in series on the switchboard in the simulation program. Measure

the voltage across the batteries with the voltmeter by placing its

measuring pens on suitable contact surfaces. What voltage is displayed?

RESPONSE:

Examination of a resistor

The resistor in the picture below has rings with the colors brown, black, red

and gold.

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a) Use the color marking to find out the resistance of the resistor and

accuracy in ohms. Search the textbook or the internet for coding.

RESPONSE:

IMPORTANT: In the continuation of the laboratory work, use a power source

of 4.5 V and resistor with the resistance 100 ohms in the simulator.

b) Connect a resistor (100 ohms) and a power source (4.5 V) according to

below.

Use the voltmeter to measure voltage and measure the voltage above

the resistance according to the figure.

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MEASUREMENT VALUE:

To remove a meter, you can drag the meter to the right, to the box

with the meter or double-click the meter and then select yellow

trash that appears at the bottom of the table. Use one

ammeter to measure current and measure the current through

the resistance according to the figure.

MEASUREMENT VALUE:

Use voltage and current measurements as well as Ohm's law to

determine the resistance of the resistor. Report all measured values ​​and

calculations.

RESPONSE:

c) Compare the resistance the simulator says the resistance has with it

you have calculated in sub-task b. Are they the same? If not, what can it do?

depends on?

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RESPONSE:

4. Series connection of resistors

Connect a circuit with two resistors (both of 100 ohms) and

the power source (4.5 V) in series according to the figure.

a) Measure the voltage across each of the resistors and the voltage

over both resistors.

VOLTAGE OVER R1:

VOLTAGE OVER R2:

VOLTAGE OVER R1 and R2:

Is it true that the sum of the voltage drops across resistor 1 and

resistor 2 is equal to the whole voltage drop across both resistors?

RESPONSE:

b) Measure the current in the circuit.

POWER THROUGH THE RESISTORS:

Use the voltage drop across both resistors and the current through

resistances and Ohm's law to calculate the compensation resistance

for the two resistors in series.

RESPONSE:

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c) Calculate the replacement resistance of the two resistors in series

theoretically using that you know the resistance of each individual resistor.

Also report calculation.

RESPONSE:

d) Do the answers in sub-tasks b and c correspond? Should the answers be accurate

equal?

RESPONSE:

5. Parallel connection of resistors

Connect a circuit with two resistors (both 100 ohms) and

the power source (4.5 V) in parallel according to the figure.

a) Measure the current through each of the resistors and the current

through the power source.

CURRENT THROUGH R1:

CURRENT THROUGH R2:

POWER THROUGH THE POWER SOURCE:

Is it true that the sum of the currents through resistors 1 and

resistor 2 is equal to the current through the current source?

RESPONSE:

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b) Measure the voltage across one of the resistors or the power source. Playing it

does it matter which one you choose?

VOLTAGE:

Use the voltage drop and current through the power source as well

Ohm's law to calculate the compensation resistance for the two

parallel-connected resistors.

RESPONSE:

c) Calculate the replacement resistance for the two connected in parallel

resistances theoretically using that you know each individual

resistance resistance. Also report calculation.

RESPONSE:

d) Do the answers in sub-tasks b and c correspond? Should the answers be accurate

equal?

RESPONSE:

6. Replacement resistance for more complicated circuits

In the following circuit, each resistor has a resistance of 100 ohms.

The replacement resistance of the circuit can be measured or calculated

theoretically with knowledge of the resistances of input resistors.

If you do not want an exact value, you can take advantage of the fact that

two series-connected resistors have greater resistance than each

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resistors in the series connection have and two resistors connected in parallel

has a lower resistance than that of any resistor in the parallel connection.

How large is the compensation resistance for the circuit with the three

the resistors? Choose one of the options.

Less than 100 ohms.

2. Between 100 and 200 ohms.

3. Between 200 and 300 ohms.

4. More than 300 ohms.

2. Exercise 1 (Laboratory 1)

Chemistry 1

Preparations

Produce about 20 ice cubes and look for a thermometer. For this laboratory you also need a stove or similar and a heat-resistant container (saucepan can be used).

Performance

Here you should heat the ice cubes until the water evaporates.

Crush the ice cubes into an ice slurry and pour the slurry into the container. Place the beaker on the heat source, turn on maximum heat. Measure the temperature throughout the experiment, preferably at a well-chosen interval. Your experiment is complete when your water changes to gaseous form.

Draw a graph of how the temperature of the water changes over time.

You can draw this graph either by hand or with aids

Think about the questions below:

What happens to the water molecules, when the temperature rises?

How come the curve looks the way it does?

What types of bonds do we encounter and what happens to these?

What distinguishes a phase change from a chemical reaction?

A few words along the way:

Think about what happens at the molecular level with bonds within or / and between the molecules.

Accounting:

The account of this task is included as part of the exercise that you will soon do (Exercise 1 - chapters 1-5).

However, you should upload your curve in this task.

Upload your curve below and then send the assignment to your teacher.

3. Laboratory 2 - separate substances

Chemistry 1

Your task in this lab is to separate a mixture of salt and sand.

You have to figure out for yourself how to do this.

So the first thing you should do is formulate a hypothesis on how you could do to separate salt and sand. Then test this hypothesis.

- Get 1 dl of sand from an area nearby, preferably fine-grained sand. Measure out 1 dl of salt in another beaker and mix the sand and salt thoroughly in a larger vessel.

- The task now means that you must separate the two substances present in the mixture in the best possible way. Use the materials you have at home and test yourself to a good method.

 Reporting of the task

Describe how to proceed and what happens in the box below. It is also possible to write this in a document which you then upload below.

This text should be at least 150 words long. Do not forget that you work with chemistry, so remember to explain what happens in each step with good chemical explanations. Check out the assessment matrix below, so you get everything that is expected in your report.

Take a picture of or draw your implementation. Attach this below.

Tip: Take cards, load them on your computer and save them so that they take up less space. Put them in a pdf or redo them in paint or similar so that several images can be included in a document. Save the images in .png, gif, jpg, jpeg if you do not select .pdf. Remember to number the pictures and explain what the pictures show.

this task tests the following central course content:

Models and theories for the structure and classification of matter.

Chemical bonding and its effect on, for example, the presence, properties and uses of organic and inorganic substances.

The significance of the experimental work for testing, re-evaluating and revising hypotheses, theories and models.

How problems and issues are delimited and studied with the help of chemical reasoning.

Planning and implementation of experiments as well as formulation and testing of hypotheses in connection with these.

Evaluation of results and conclusions through analysis of method choice, work process and sources of error.

4. Hypothesis, before the lab: Analysis of unknown salt Chemistry 1

Brief introduction to the task:

In this assignment, you must write a hypothesis for the laboratory work you will later carry out. You must also make a risk assessment and draw a flow chart of the laboratory.

NOTE: You must have submitted this information before you start the laboratory analysis of unknown salt, otherwise the whole purpose of the information falls away.

A hypothesis is a qualified assumption about reality, this means that you can not just guess what is going to happen and write it down. So you need to find out more about how to identify different salts. If you have difficulty getting started and need guidance to reach a hypothesis, call or email your teacher. For those of you who are looking for higher grade levels, you should formulate this hypothesis on your own. The idea here is that you should formulate a hypothesis about how you could do to identify an unknown salt. So you should not write a hypothesis about what the unknown salt can be but what method (s) you can use to find out an unknown salt.

NOTE! Assume that the ions that the unknown salt consists of are represented in the known salts that you have to start from.

Theory background

It is good to know something about how different salts dissolve in different solvents and what colors the different ions or salts have. In general, it is good to find out what special properties the different salts have.

A common task for a chemist is to identify or determine the composition of an unknown substance. During this lab, you need to think about different methods to determine what an unknown sample (salt) consists of. Determining the composition is called qualitative analysis.

You need to think about what features you can test. What properties distinguish the ions that you have in your salt from other ions. Use your knowledge of the periodic table and immerse yourself in different salts and what properties the constituent ions possess.

Materials you have to start from:

Here you can start from what you can find in a normally equipped laboratory. This means that there will be access to beakers, spatulas, platinum wire, spoons, clean water, burners, pipettes, measuring flasks, measuring glasses.

Chemicals you have to start from:

- A container containing "Unknown salt".

- 11 containers with known salts in solid form. These salts are: NaHCO3, NaNO3, NaCl, NaI, KCl, KNO3, K2CO3, Ca (NO3) 2, LiCl, SrCl2, Cu (NO3) 2 ∙ 3H2O

- 8 containers with known saline solutions. These brines are NaHCO 3 (aq), NaCl (aq), NaI (aq), KCl (aq), KNO 3 (aq), K 2 CO 3 (aq), AgNO 3 (aq), BaCl 2 (aq).

Nitric acid

Nitric acid is corrosive!

What is a hypothesis

About Risk Analysis

example of a template for making a risk assessment for several subjects

The presentation of the task:

Write a hypothesis in the box below

Upload your security analysis, use the security form above for your security analysis. Remember to include all the topics you use in your flowchart in this safety analysis.

Upload your flow chart

The hypothesis

Flow chart

Security analysis?

The task is assessed as follows:

In this matrix, your teacher will select a box for each row. This box indicates how you have succeeded in the given area. The idea is that you should see what you need to work on and what you do well. If you do not have a selection, you generally need to complete that part to complete the task. It is a rising scale where the basic parts are on the left.

So work with the matrix, it tells you based on what your task is assessed.

Your teacher will comment on specific things in the response, if there is something that needs to be addressed and if the teacher puts an assessment on the task, this is to give you and the teacher an indication of how well you succeeded with this part based on what is expected and prescribed. knowledge requirements. If your goal differs from the assessment, the matrix tells you what you missed.

In this assignment, the following central course content is tested:

Precipitation reactions.

Qualitative and quantitative methods for chemical analysis.

Planning and implementation of experiments as well as formulation and testing of hypotheses in connection with these.

5. Laboratory 3 - Indicator

Chemistry 1

The task summarized:

Follow the Execution described below, however, it is perfectly okay if you think you need to change or improve the method. In that case, do not forget to explain this. You should test the color of a natural pH indicator at different pH. Choose one of the vegetables in "Table: Color scale for some natural indicators" to make your indicator solution from. Remember to choose an indicator that has several color shades.

This laboratory work must be reported in the form of a laboratory report. In this report, you get the opportunity to practice formulating questions and purpose and show that you are aware of the chemistry behind these phenomena. Here you also get to show that you can explain what happens to chemical concepts. You will need to explain several parts for example -What is an indicator? -How exactly does your indicator work? -How does pH really work? -What is the pH scale? -What is an acid and a base?

A short theoretical review of the lab.

"A pH indicator shows whether a solution is acidic, basic or neutral. It is often a weak acid or base that changes color when they bind hydrogen ions (H +) or hydroxide ions (OH-). Indicators are used in titration when examples should determine the buffer capacity of a solution.

Most pH indicators are organic molecules that contain conjugated double bonds. When a protonation / deprotonation takes place during the conjugation, the absorption wavelengths of the molecule are shifted, which causes the color change ".

Read about pH and acids and bases in the book so that you know a little more about this and check out this page:

Many substances in nature change color depending on the pH. Examples of such substances are found in many plants such as red cabbage, beets, cherries, tulip petals and yellow onions.

Performance:

Make an indicator solution by cutting a number of pieces of the selected indicator and boiling them with just enough water for a few minutes (use as much water as the indicator). Pour off the solution and allow to cool. This is now your indicator solution and now it's time to test the pH of some substances you have at home.

 Before you choose which 5-10 subjects you want to investigate, you should think about this:

· The substance must be water soluble

· The substance should not be strongly colored

If you now drop a few drops of your indicator solution into the solution of the substance you are examining, the color should reveal the pH of the substance within a few minutes. The color scale is in the table below. Now it's just to continue with other topics.

Feel free to film or take pictures of your implementation.

Table: Color scale for some natural indicators.

Reporting of the task

This laboratory work must be reported as a laboratory report. Here you can choose to write the laboratory report in a separate document which you then upload to this task or you can use the writing boxes below. Since this task is an exercise in writing a laboratory report, we have divided the writing boxes into several pieces so that each heading in the report has its own writing box.

Report Laboratory 3 - indicator

Introduction:

Theory background- Here you describe "facts", scientific connections, explain concepts that are relevant to understanding your particular laboratory.

For example, you could explain: What is an indicator? How does pH really work? What is the pH scale? What is an acid and a base?

Purpose: Here you should write very briefly what is the purpose of your laboratory. Why do you want to conduct the survey?

Number of words: 0

Question: The question can be a question or a couple of questions that you want to try to answer with your survey.

Number of words: 0

Materials: Explain which material, in what amount, you have used in your laboratory.

Number of words: 0

Method: Describe how you proceeded when you did your laboratory work. Remember to write in running text and in the past tense, ie you must explain how you did. If possible, also avoid I / you / we / man forms.

Here you can also upload any photos you have taken of the version.

(Tip: Take cards, load them on the computer and save them so that they take up less space. Put them in a pdf or redo them in paint or similar so that several pictures can be included in a document. Save the pictures in .png if you do not select .pdf and you have to upload these to the student page, remember to number the pictures and explain what the pictures show.)

File upload

Number of words: 0

Results:

Here you describe your result for the different solutions on which you have tested your indicator. For this laboratory, it is a good idea to present the results with the help of pictures and a table. You can upload these below.

Number of words: 0

File upload

Discussion: Discuss the result. Explain the result, link results to the purpose of the laboratory, link results to the theoretical background, link your result to reality, and so on.

Justify your conclusions with reasoning.

Discuss the method and sources of error. Are there better ways to carry out the laboratory work? Were there any difficulties in the execution that may have affected the result? etc.

Number of words: 0

Source list: Use at least two different sources. Never just Wikipedia

Number of words: 0

Source criticism:

Here you should critically review the sources you have used to write your report. How credible is the source? The author? What was the purpose of the author when the source was written? Is it first-hand or second-hand information? etc.

If you are unsure of what it means to be source critical, then take an extra look at the powerpoint presentation "Source Criticism" which is among your course accessories.

Number of words: 0

If you would rather write the report in your own document, this is also fine. Then you can upload it below.

File upload

Indicator.docx

Assessment of the task

In the matrix below, your teacher will select a box for each row. This box indicates how well you have succeeded in the given area. The idea is that you should see what you need to work on and what you do well. If something is marked as an "F", you generally need to complete that part to complete the task. It is a rising scale where the basic parts are on the left.

So work with the matrix, it tells you what your task is judged from.

Your teacher will comment on specific things in the response, if there is anything that needs to be addressed. Sometimes it is not possible to put a summary judgment on the whole task because the student may succeed very well in some parts and less well in other parts. If the teacher puts an assessment on the task, this is to give you and the teacher an indication of how well you have succeeded with this task based on the expected and prescribed knowledge requirements. If your goal differs from the assessment, the matrix tells you what you missed. If you need to complete something in the assignment, your teacher will tell you this in the response.

In this assignment, the following central course content is tested:

What characterizes a scientific issue.

How problems and issues are delimited and studied with the help of chemical reasoning.

Planning and implementation of experiments as well as formulation and testing of hypotheses in connection with these.

Evaluation of results and conclusions through analysis of method choice, work process and sources of error.

Acid-base reactions, including the pH concept and buffering action.

The significance of the experimental work for testing, re-evaluating and revising hypotheses, theories and models.

6. Diagnostic test chapter 7

Chemistry 1

You have hydrochloric acid with a concentration of 0.40 mol / dm3 and an aqueous solution of sodium hydroxide with a concentration of 0.20 mol / dm3. In a beaker, mix 30 cm3 of the hydrochloric acid with 50 cm3 of the sodium hydroxide solution.

What pH does the mixture get?

Rank the fluids below according to the ability to conduct electrical current. Write the fluid with the best conductivity first.

aqueous solution of acetic acid with a concentration of 0.15 mol / dm3

aqueous solution of acetic acid with a concentration of 0.2 mol / dm3

pure acetic acid

aqueous solution of nitric acid with a concentration of 0.2 mol / dm3

Magnesium is a base metal that reacts in hydrochloric acid to form hydrogen and magnesium ions Mg2 +. Write a balanced formula for this reaction.

You should dissolve 10 g of calcium carbonate in hydrochloric acid. What volume of hydrochloric acid with a concentration of 2.0 mol / dm3 do you have to take at least?

For 10 g of CaCo3 the amount of substance is 0.1 mol, then the amount of HCl which solves the problem is 2 * 0.1 = 0.2.

Then I use this formula: n / c = V

0.2 / 2 = 0.1

the answer is 0.1 dm ^ 3 is the amount of hydrochloric acid needed

Number of words: 48

Each of the following properties applies to any of the acids hydrochloric acid, sulfuric acid, nitric acid, acetic acid and carbonic acid. Combine each property with the right acid.

 The acidic aqueous solution contains chloride ions.

Formed during combustion of e.g. PVC plastic.

Available in car batteries.

The alcohol is converted to when wine sours.

Should be stored in dark bottles.

Smokes in humid air.

Included together with nitric acid in king water.

Forms nitrous gases together with metals.

Has the formula H2CO3.

Number of words: 0

To an E-flask with hydrochloric acid, add so much sodium hydroxide solution that the contents of the flask become neutral.

Write a reaction formula for the reaction that takes place in the E-flask.

If you boil off the water in the E-flask after neutralization, a solid salt remains. What name and formula does this salt have?

Number of words: 0

3.0 dm3 hydrochloric acid with a concentration of 0.50 mol / dm3 must be neutralized by adding solid sodium hydroxide. How much sodium hydroxide is needed?

Write the name and formula for the ions present in a solution of nitric acid.

You must prepare 200 cm3 of hydrochloric acid so that its pH is 2.0. At your disposal you have hydrochloric acid with a concentration of 0.400 mol / dm3. How much volume of this hydrochloric acid should you measure and then dilute with distilled water?

Number of words: 0

KW = 5.5 · 10–14 (mol / dm3) 2 at 50 ° C.

What is the concentration of oxonium ion in distilled water at 50 ° C?

What is the hydroxide ion concentration in distilled water at 50 ° C?

How does the oxonium ion concentration in pure water change if the temperature is raised?

Number of words: 0

In an E-flask you have 40 cm3 of hydrochloric acid with a concentration of 0.30 mol / dm3. To this you add dropwise a solution of sodium hydroxide until the acid has been neutralized. How much volume of NaOH solution is used if it has a concentration of 0.20 mol / dm3?

Calcium carbonate is a sparingly soluble salt in water. If you drop hydrochloric acid into the mixture, it starts to bubble.

a) What gas is formed?

b) In addition to the gas, water and a salt are formed. Write a balanced reaction formula for the reaction.

In nature, there is calcium carbonate in the form of marble or limestone as it is called. The chemical mixture is calcium carbonate. If you drop hydrochloric acid on limestone, it begins to foam and carbon dioxide is formed

Number of words: 30

Calculate [H3O +] in solutions with the following pH values

3.45

9.15

2.3

0.25

7.1

5.3

Number of words: 0

Each of the following properties applies to any of the acids hydrochloric acid, sulfuric acid, nitric acid, acetic acid and carbonic acid. Combine each property with the right acid.

Forms carbon dioxide when heated.

Light yellow nails and skin.

The anion of the acid is called acetate ion and is abbreviated Ac-.

Called in aqueous solution hydrochloric acid.

A biprotic acid which in its second protolysis step forms sulphate ions.

Number of words: 0

Calculate the hydroxide ion concentration in solutions with the following pH values. KW = 1.00 · 10–14 (mol / dm3) 2.

pH = 3.14

pH = 8.31

pH = 13.2

Number of words: 0

An aqueous solution of potassium hydroxide KOH has a concentration of 0.30 mol / dm 3.

KW = 1.0 · 10 –14 (mol / dm 3) 2.

Calculate [OH-] in the solution.

Calculate [H 3 O +] in the solution.

Number of words: 0

What is the difference between a strong and a weak acid?

the difference between a strong and a weak acid is at strong acid all molecules will release hydrogen ions, while in weak acid only a few molecules will split

Sulfuric acid is a biprotic acid that is protolyzed in two steps according to the reaction formulas in the section Sulfuric acid. Phosphoric acid H3PO4 is a three-protonic acid that is protolyzed in three steps in a corresponding manner.

Write the three reaction formulas for the protolysis of phosphoric acid in water.

Compare the acid strength of the three acids and explain the ranking.

You have access to hydrochloric acid with a concentration of 9 mol / dm3. You have access to hydrochloric acid with a concentration of 9 mol / dm3. How large a volume of hydrochloric acid should be measured and diluted with water if you want to prepare 1.0 dm3 hydrochloric acid with a concentration of 2.0 mol / dm3?

Number of words: 0

Calculate the pH of aqueous solutions whose oxonium ion concentration is

2.0 mol / dm3

0.001 mol / dm3

1 · 10–7 mol / dm3

3.5 mol / dm3

0.20 mol / dm3

3.2 · 10–3 mol / dm3

4.22 · 10–6 mol / dm3

7.1 · 10–2 mol / dm3

Number of words: 0

Write the formula for the corresponding acid to:

a) OH-

b) NO3-

c) PO43-

d) O2-

You have 200 cm3 of hydrochloric acid with pH 3.0. What pH does hydrochloric acid get if it is diluted with distilled water to double volume?

You dissolve 12 g of barium hydroxide in water and dilute to a volume of 3.5 dm3. What is the hydroxide ion concentration of the solution?

7. Exercise 2 chapters 6-7

Chemistry 1

When sodium metal reacts with water, sodium ions, hydroxide ions and hydrogen gas are formed.

The reaction that takes place looks like this:

2Na + 2H2O -> H2 (g) + 2OH- + 2Na +

Indicate whether the solution reacts acidic, neutral or alkaline and justify your answer.

Number of words: 0

The metal chromium can be prepared from chromium oxide by the reaction formula:

2Al + Cr2O3 -> Al2O3 + 2Cr

A large excess of aluminum is usually used in the production.

How much mass of aluminum should be used to produce 50 g of chromium if you want it to be 3 times the equivalent mass of aluminum, ie 3 times the mass of aluminum that is theoretically needed.

Number of words: 0

Which statement (s) about an acid and what is a base is correct?

An acid is a molecule that releases a hydrogen ion in a chemical reaction

An acid is a proton donor

A base picks up a proton in a chemical reaction

A base receives a hydrogen ion in a chemical reaction

An acid is a proton acceptor

Calculate the mass of the CO2 formed when 10 g of C5H12 reacts with O2 according to the reaction formula:

C5H12 + 8O2 -> 5CO2 + 6H2O

First calculate the amount of substance C5H12 based on:

Number of words: 0

What is the amount of CO2 that can be formed?

Number of words: 0

What will be the mass of CO2 formed?

Number of words: 0

The following solutions are mixed: 25 cm3 of barium chloride solution with a concentration of 0.02 mol / dm3 and 25 cm3 of silver nitrate solution with a concentration of 0.02 mol / dm3.

Calculate the mass of the precipitate that arises.

Start by writing a reaction formula for the precipitation reaction.

Mark in your formula which salts are in solution (aq) or form precipitate (s).

Number of words: 0

Calculate the amount of substance for the salts you use as a starting point.

Then calculate the substance amounts of the current ions.

Number of words: 0

How much substance will be formed by the precipitate that arises?

Number of words: 0

What will be the mass of the precipitate?

Number of words: 0

Calculate the mass of water formed if a mixture of 75 g of hydrogen and 200 g of oxygen explodes.

First write a reaction formula for the reaction:

Number of words: 0

Then calculate the amount of substance oxygen and hydrogen based on.

Number of words: 0

Is any of the substances involved in the reaction limiting the amount of water that can be formed? If - if so, which one?

Number of words: 0

How much water will be formed?

Number of words: 0

How much does the water formed weigh?

Number of words: 0

Which of the following statements is true?

If the volume increases, the gas pressure decreases proportionally

All three options are correct

If the amount of substance increases, the gas pressure decreases proportionally

If the temperature increases, the gas pressure decreases proportionally

What is the concentration of the different ion species in a solution of sodium sulphate solution with a concentration of 0.20 mol / dm3.

0.40 mol / dm3 sodium ions and 0.20 mol / dm3 sulphate ions

0.20 mol / dm3 sodium ions and 0.40 mol / dm3 sulphate ions

2 mol / dm3 sulphate ions and 1 mol / dm3 sodium ions

1 mol / dm3 sulphate ions and 2 mol / dm3 sodium ions

Tell us how you think in this task

Number of words: 0

Calculate the amount of substance of the solute in the following solutions.

1) 2 dm3 KCl (aq) concentration 0.5 mol / dm3

Number of words: 0

2) 1.5 dm3 NaOH (aq) concentration 2 mol / dm3

Number of words: 0

3) 750 cm 3 HCl (aq) concentration 3 mol / dm 3

Number of words: 0

4) 100 cm 3 Na 2 CO 3 (aq) concentration 4 mol / dm 3

Number of words: 0

Calculate the amount of hydrogen atoms in 1.0 mol of ethane, C2H6.

1.0 mol

6.0 mol

0.55 mol

5.50 mol

To 30.0 cm 3 of a sulfuric acid solution of unknown concentration was added sodium hydroxide solution with a concentration of 0.25 mol / dm 3. The sulfuric acid was completely neutralized when 21.5 cm 3 of the hydroxide solution was added. Calculate the concentration of sulfuric acid.

Number of words: 0

Which two particles react as acids in the following equilibrium?

HPO42- + H2O <--> H2PO4- + OH-

OH-

H2O

H2PO4

HPO4-

One beaker contains 200 ml of water. 150 mg of sodium are added and a violent reaction takes place. In connection with this, a strong hydrogen evolution is observed.

The reaction that takes place looks like this:

2Na + 2H2O -> H2 (g) + 2OH- + 2Na +

a) Determine the pH of the solution.

Here you need to make calculations in several steps.

First, you need to calculate the amount of sodium you are starting from. What will be the amount of sodium?

Number of words: 0

Based on this, the amount of substance hydroxide ions can be determined. What will be the amount of hydroxide ions?

Number of words: 0

Now the concentration of hydroxide ions can be calculated. What will be the concentration of hydroxide ions?

Number of words: 0

When the concentration of hydroxide ions is present, the pH of the solution can be calculated. What will be the pH value?

Number of words: 0

b) Calculate the volume of hydrogen formed during the reaction. The molar volume at the prevailing ratio is 24.5 dm3 / mol.

In a combustion reaction, 100 g of pentane, C5H1, were left

In a combustion reaction, 100 g of pentane, C5H12, were completely reacted with oxygen. Upon complete combustion, water and carbon dioxide are formed.

How much carbon dioxide can be formed from this reaction?

Assume that the reaction takes place at normal air pressure and room temperature (25 degrees C and 100kPa).

The first thing you need to do is write a reaction formula for the reaction.

Write the balanced reaction formula in the box below:

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Then calculate the amount of substance pentane based on:

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Then calculate the amount of CO2 that can be formed.

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Using the general gas law, the volume can then be calculated:

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How much mass of the solid salt CuSO4 x 5 H2O should be weighed to prepare 2.0 dm3 of a solution with a concentration of 0.15 mol / dm3?

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Calculate the pH in the following:

0.10 mol / dm3 hydrochloric acid

0.10 mol / dm3 sulfuric acid

0.10 mol / dm3 sodium hydroxide

Assume that the solutions are at normal room temperature (25 degrees Celsius).

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Hello, we have some questions for you regarding the design of the test and whether you need my help:

Did the task test what you expected based on the instructions we gave you?

Is there anything being tested in this task that you feel you do not know and need my help to understand?

Is there anything in this task that you think we need to change?

Thanks for your help. Fill in your answers in the box below, do this after you have finished the test but before you submit. This takes a maximum of a few minutes and then it is of course okay for you to submit the sample a few minutes late. Now read more about the assessment:

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Assessment of the task

In the matrix below, your teacher will select a box for each row. This box indicates how well you passed the test. The idea is that you should see what you need to work on and what you do well. If you do not have a selection, you generally need to complete that part to complete the task. It is a rising scale where the basic parts are on the left.

So look at the matrix, it tells you what your task is judged from.

Your teacher will comment on specific things in the response, if there is anything that needs to be addressed. Sometimes it is not possible to put a summary judgment on the whole task because the student may succeed very well in some parts and do less well in other parts. If the teacher puts an assessment on the task, this is to give you and the teacher an indication of how well you have succeeded with this task based on the expected and prescribed knowledge requirements. If your goal differs from the assessment, the matrix tells you what you missed.

In this subtest, the following central course content is tested:

Interpretation and writing of formulas for chemical compounds and reactions.

Substance quantity ratios, concentrations, limiting reactants and chemical reaction yields.

Acid-base reactions, including the pH concept and buffering action.

8. Laboratory 4 - Thermal decomposition

Here you need to show that you master calculations, formula writing and have a laboratory approach. In your presentation of calculations and reflections, you can reach all grading steps. From the results of the weighings, you can then use calculations to determine which of the reaction formulas A - F is the correct one.

Accounting

This laboratory work is reported by filling in the writing boxes below. In these, do the following:

- Present your result (mass after decomposition)

- Balance the reaction formulas

- Calculate theoretical masses

- Present your conclusion and justify it.

- Discuss the method and the reliability of your conclusion.

If you would rather do this in a separate document instead of in the writing boxes below, it also works well. In that case, upload your document here.

File upload

Questions to answer / discuss:

1. What was the mass of your product after the thermal decomposition?

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2. This is what the proposed formulas look like:

A. sodium bicarbonate (s) -> sodium (s) + water (g) + oxygen (g) + carbon dioxide (g)

B sodium bicarbonate (s) -> sodium oxide (s) + water (g) + carbon dioxide (g)

C sodium bicarbonate (s) -> sodium carbonate (s) + water (g) + carbon dioxide (g)

D sodium bicarbonate (s) -> sodium oxide (s) + hydrogen (g) + oxygen (g) + carbon monoxide (g)

E sodium bicarbonate (s) -> sodium hydroxide (s) + carbon dioxide (g)

F sodium bicarbonate (s) -> sodium (s) + carbon (s) + oxygen (g) + hydrogen (g)

Balance these and enter the balanced formulas A-F in the box below or upload a document with your balanced formulas:

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File upload

Thermal decomposition of sodium bicarbonate.docx

Calculate the theoretical masses of the solid end products in formulas A-F.

Enter these in the writing box below.

You upload the calculations.

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File upload

4. What is formed during thermal decomposition of sodium bicarbonate?

Present your conclusion, clearly justify how you arrive at this.

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5. How confident can you be of your conclusion?

Here you should discuss sources of error that may have affected your results.

Feel free to give suggestions on how to improve the laboratory.

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Assessment of the task

In the matrix below, your teacher will select a box for each row. This box indicates how well you have succeeded in the given area. The idea is that you should see what you need to work on and what you do well. If you have not achieved at least E, you generally need to complete that part to complete the task. It is a rising scale where the basic parts are on the left.

So work with the matrix, it tells you what your task is judged from.

Your teacher will comment on specific things in the response, if there is anything that needs to be addressed. Sometimes it is not possible to put a summary judgment on the whole task because the student may succeed very well in some parts and less well in other parts. If the teacher puts an assessment on the task, this is to give you and the teacher an indication of how well you have succeeded with this task based on the expected and prescribed knowledge requirements. If your goal differs from the assessment, the matrix tells you what you missed. If you need to complete something in the assignment, your teacher will tell you this in the response.

In this assignment, the following central course content is tested:

Interpretation and writing of formulas for chemical compounds and reactions.

Substance quantity ratios, concentrations, limiting reactants and chemical reaction yields.

Qualitative and quantitative methods for chemical analysis, for example gravimetric analysis.

How problems and issues are delimited and studied with the help of chemical reasoning.

Planning and implementation of experiments as well as formulation and testing of hypotheses in connection with these.

Evaluation of results and conclusions through analysis of method choice, work process and sources of error.

9. Diagnostic test chapter 9

Chemistry 1

Write the formula for

copper (I) oxide

tin (IV) chloride

silver (II) oxide

iron (III) nitrate

manganese (II) oxide

1 Cu₂O

2 SnCl4

3 Ag2O

4 Fe (NO3) 3

5 MnO

Number of words: 10

Name the following chemical compounds using oxidation numbers (eg CuO is called copper (II) oxide).

FeO

Cr2O3

FeSO4

CrO3

Fe2 (SO4) 3

MnO2

CuO

AgNO3

 Iron (II) oxide

 Chromium (III) oxide / Chromium oxide green

Ferrous sulfate

Chromium trioxide

Iron (III) sulfate

Manganese dioxide

Copper (II) oxide

Silver nitrate

Number of words: 9

What becomes emf at the normal state of a galvanic element consisting of the following half-cells:

Zn2 + / Zn (s) and Ni2 + / Ni (s)

Ag + / Ag (s) and Cu2 + / Cu (s)

Al3 + / Al (s) and Fe2 + / Fe (s)

Number of words: 0

Which reaction (s) below are redox reactions?

HCl (aq) + NaOH (aq) H2O (1) + NaCl (aq)

2AgNO3 (aq) + BaCl2 (aq) 2AgCl (s) + Ba (NO3) 2

Mg (s) + 2 H3O + (aq) Mg2 + (aq) + H2 (g) + 2 H2O (l)

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For each of the reactions below, indicate which atomic species is oxidized and which is reduced.

H2 + F2 2HF

2 ZnS + 3O2 2 ZnO + 2SO2

2 Cu + O2 2 CuO

Fe2O3 + 3 CO 2 Fe + 3 CO2

 CH4 + 2O2 CO2 + 2H2O

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If gold is dissolved in royal jelly (a mixture of nitric acid and hydrochloric acid), gold (III) chloride ions AuCl4 are formed - according to the incomplete reaction formula below. Write the complete and balanced formula for the reaction.

Au + NO + 4 Cl– AuCl4- + NO

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The following reaction takes place in an alkaline aqueous solution. Balance the reaction formula and supplement with H3 O + or OH - and with H2 O. Note that some chlorine atoms are oxidized and some are reduced.

ClO2 ClO2- + ClO 3-

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Enter the oxidation numbers for sulfur in:

a) S (s)

b) SO2

c) HSO4-

d) H2SO4

e) H2S

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Which of the following statements is true regarding a galvanic element with the following cell scheme?

- Ni (s) Ni2 + (aq) Ag + (aq) Ag (s) +

An oxidation occurs at the nickel electrode.

The mass of the nickel metal decreases as the element provides current.

As the element provides current, electrons in the outer circuit travel from the silver metal to the nickel metal.

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Electrolysis of sodium chloride solution is an important industrial method for the production of chlorine gas and sodium hydroxide.

Write the anode reaction for electrolysis of sodium chloride solution.

Write the cathode reaction for electrolysis of sodium chloride solution.

Write the total reaction for the electrolysis.

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We mix copper powder in chlorine water (chlorine gas dissolved in water).

a) Which substance is oxidised or reduced?

b) Write the formula for the oxidation and reduction reactions.

c) Write the formula for the total reaction.

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Copper rods are placed in aqueous solutions of lead nitrate, zinc sulphate, copper chloride and silver nitrate. In which solution (s) can one expect a layer of another metal to form on the copper rod?

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Place the pole signs in the following cell diagram:

Ag (s) Ag + (aq) Zn2 + (aq) Zn (s)

Al (s) Al3 + (aq) Cu2 + (aq) Cu (s)

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Start from the electrochemical voltage series and state which of the following statements are true.

Aluminum is a stronger reducing agent than iron.

Iron is a nobler metal than copper.

Copper metal reacts spontaneously with silver ions if placed in an aqueous solution of silver nitrate.

Copper metal reacts spontaneously with magnesium ions.

If you put copper in hydrochloric acid, the metal dissolves.

Iron can be dissolved in hydrochloric acid.

If an aqueous solution of barium chloride is mixed with hydrochloric acid, a reaction takes place when hydrogen gas is formed.

7

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In which direction are the following reactions going? Replace the lines with reaction arrows pointing in the right direction.

Pb2 + (aq) + Cu (s) Pb (s) + Cu2 + (aq)

Cu2 + (aq) + Zn (s) Cu (s) + Zn2 + (aq)

Zn2 + (aq) + H2 (g) Zn (s) + 2 H + (aq)

10. Laboratory 5 Rusting steel wool

Chemistry 1

Many of the materials we use in everyday life and in industry consist of metals. Unfortunately, metals often have the ability to rust / corrode and these metal objects that we use then become brittle and can break. In this laboratory, you will investigate how steel wool (or iron wire) reacts in different aqueous solutions.

In this laboratory, you should be able to investigate this with rust formation. The laboratory must be reported as a complete laboratory report.

Here you have the instructions for the laboratory, click on the link below:

Laboratory 5 Rusting steel wool.pdf

Below you will find links with information that can be good to look through.

Instructions Report Writing (6).

Source criticism

If you have taken pictures during your laboratory work, a tip may be to include them / one of them in your laboratory report.

You can choose to write your report in the writing box below or upload your report in a document.

Assessment of the task

In the matrix below, your teacher will select a box for each row. This box indicates how well you have succeeded in the given area. The idea is that you should see what you need to work on and what you do well. If something is marked as an "F", you generally need to complete that part to complete the task. It is a rising scale where the basic parts are on the left.

So work with the matrix, it tells you what your task is judged from.

Your teacher will comment on specific things in the response, if there is anything that needs to be addressed. Sometimes it is not possible to put a summary judgment on the whole task because the student may succeed very well in some parts and less well in other parts. If the teacher puts an assessment on the task, this is to give you and the teacher an indication of how well you have succeeded with this task based on the expected and prescribed knowledge requirements. If your goal differs from the assessment, the matrix tells you what you missed. If you need to complete something in the assignment, your teacher will tell you this in the response.

In this assignment, the following central course content is tested:

What characterizes a scientific issue.

How problems and issues are delimited and studied with the help of chemical reasoning.

Planning and implementation of experiments as well as formulation and testing of hypotheses in connection with these.

Evaluation of results and conclusions through analysis of method choice, work process and sources of error.

Redox reactions, including electrochemistry.

The significance of the experimental work for testing, re-evaluating and revising hypotheses, theories and models.

11. Laboratory 6 (home lab): Analysis of unknown salt

Chemistry 1

Laboratory: Analysis of unknown salt

Theory

A common task for a chemist is to identify or determine the composition of an unknown substance. Determining the composition is called qualitative analysis.

The purpose of this lab is to determine the composition of an unknown salt by using your knowledge of the properties of salts and ions.

Task

To perform qualitative analyzes in order to then identify an unknown salt and report this.

Equipment

This lab is theoretical, so you will not perform the lab yourself. Here you will instead get given values. Based on these, you should come to a conclusion about which ions are included in the unknown salt.

Those who have performed this laboratory have had access to the following:

- Platinum wire for low color testing

- Pipettes

- Cup

- Burner

- Spatula

Chemicals

- Ethanol

- HNO3

- AgNO3 (aq)

11 known salts in solid form: NaHCO 3, NaNO 3, NaCl, NaI, KCl, KNO 3, K 2 CO 3, Ca (NO 3) 2, LiCl, SrCl 2, Cu (NO 3) 2 ∙ 3H 2 O

6 known saline solutions: NaHCO 3 (aq), NaCl (aq), NaI (aq), KCl (aq), KNO 3 (aq), K 2 CO 3 (aq).

- Unknown salt

Performance

You have previously written a hypothesis and made a flow chart for this laboratory. Regardless of what you have written in your hypothesis, it is now the intention that in your reasoning you should start from the method shown in the instructions below. See the instructions in the link below.

Instruction Analysis of unknown salt.pdf

Based on this method, results will be reported. Based on these results, you should answer and discuss a couple of questions.

In the document below you can see the results from the low color test.

Low test Result.pdf

Below are pictures from the "Silver Nitrate Test". The silver nitrate test involves a precipitation experiment and the addition of nitric acid.

Three images are shown below.

Figure 1: Saline solutions only.

Figure 2: The solutions after the addition of silver nitrate, AgNO3.

Figure 3: After addition of nitric acid, HNO3.

It is the top row of the test plate used here, so it is the 6 small "cups" at the top you should look at. If you think the image is small, you can enlarge it by clicking "Ctrl z".

FIGURE 1: The image shows the small cups when only the saline solutions are added.

The contents of the beakers, from left to right, are:

NaHCO3 (aq)

2. KNO3 (aq)

3. KCl (aq)

4. NaI (aq)

5. K2CO3 (aq)

6. Unknown salt (aq)

FIGURE 2: shows the small beakers with saline solutions after the addition of silver nitrate.

FIGURE 3: shows results after addition of nitric acid, HNO3.

Summarize the results from the tests below, fill in the boxes:

(For the silver nitrate test, you can enter "F" for precipitation and "IF" for no precipitation)

Subject: low color: Silver nitrate test: Acid test:

LiCl

NaHCO3

NaI

KCl

NaCl

KNO3

SrCl2

NaNO3

Ca (NO3) 2

Cu (NO3) 2

K2CO3

Unknown salt

What is one ion of the unknown salt?

Li

Na

K

Sr.

Ca

Cu

What is the second ion of the unknown salt?

Nitrate

Carbonate

Hydrogen carbonate

Chloride

Iodine

Now you have come to a conclusion about what the unknown salt is for salt. Describe in the box below how you arrive at your conclusion.

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Previously, you had to formulate a hypothesis on how one could do to analyze an unknown salt. Was there anything you suggested in your hypothesis that is not included in the method on which this task is based?

Yes

No

Motivate.

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Was there anything in this lab that was done that you had not suggested?

Yes

No

Motivate.

Number of words: 0

Are the results you have had to assume in this task reliable or can there be something that may have affected the results?

Number of words: 0

Assessment of the task

In the matrix below, your teacher will select a box for each row. This box indicates how well you passed the test. The idea is that you should see what you need to work on and what you do well. If you do not have a selection, you generally need to complete that part to complete the task. It is a rising scale where the basic parts are on the left.

So look at the matrix, it tells you what your task is judged from.

Your teacher will comment on specific things in the response, if there is anything that needs to be addressed. Sometimes it is not possible to put a summary judgment on the whole task because the student may succeed very well in some parts and do less well in other parts. If the teacher puts an assessment on the task, this is to give you and the teacher an indication of how well you have succeeded with this task based on the expected and prescribed knowledge requirements. If your goal differs from the assessment, the matrix tells you what you missed.

In this task, the following central is tested

12. Physics 2

Make a Laboration about Movement

Laboratory 2: Magnetism and induction

Laboratory 3: Harmonic oscillation

Laboratory 4: Light