Qualitative analysis of cations lab report answers

Lab Report

Approach:

Lab is intended to reinforce the chemical principles learned in class through experimentation. At the beginning of every lab I will 1) introduce the basic theory behind each lab; 2) point out any trouble spots, points of interest, and mistakes in the lab; and 3) show you how to use the lab equipment. I will not, however, tell you how to do the lab. I believe part of learning is discovery and trial and error. Experiments are not to be done on the basis of a cookbook.

Lab Objectives:

l) Learn the Scientific Method – Process by which a hypothesis is created and tested.

2) Develop Inductive Reasoning Skills - Experimentation is greater than theory.

3) Develop Technical Writing Skills - The ability to effectively convey evidence to others and to interpret another’s data.

4) Learn basic chemical principles and develop a chemical intuition

Lab Materials:

1) Lab Notebook

2) Lab Manual (Experiments and Measurements)

3) Goggles

4) Appropriate lab attire (as stated in the safety sheet)

5) USB drive

Attendance:
Attendance in lab is MANDATORY. If you are sick or have a conflict you must notify me in advance (or as soon as possible) to discuss making up the lab during one of the other sections. If you have to attend another TA’s lab section, you must obtain prior permission from me and the other TA. You have to obtain the TA’s signature on your data sheet and attach that to your lab report to verify that you have attended the lab for that week. You will not receive credit for the report without this confirmation. In the event of an emergency please contact me to make special arrangements. If you have more than two absences over the course of the semester, YOU WILL NOT PASS THE LAB.
LAB PREPARATION

Prior to each lab you are expected to have read through the experiment in your lab manual and have a general understanding of what we will be doing. This prepares you so you can ask questions when I introduce the important concepts at the beginning of each lab. To ensure this is done, you will be required to take a quiz or have some sort of assignment at the beginning of each lab. This will be worth 5 points. You will be told the week before what the expectations for the following week will be.

What can the pre-lab assessment be? One of the following:

1. Quiz at the start of lab (most common)

2. A paragraph or two about what you will be doing, and what you should learn from it

What can be on the quiz?

1. Objectives & definitions

2. Safety information

3. How to complete a simplified version of the calculations

4. Basic interpretation of data you will collect in class

ACADEMIC INTEGRITY

Academic integrity is assumed. University policy states that, unless otherwise specified, students may not collaborate on graded material. While you will be working with a lab partner on the experiment in lab, each individual must write his or her own report. The first time I suspect you are writing your lab report with your lab partner/ peers or using work other than your own, you will receive a zero. Subsequent occurrences will result in a zero and you will be reported to the dean. If you have any questions about the limits of collaboration, please ask for clarification.

Outside sources must be properly cited. You do not have to cite your lab manual or your TA, however, any other source, including the Internet and your textbook (page included), must be cited. Failure to do so is considered a form of plagiarism, and will result in a zero for the report.

Where to turn in your lab report:

All lab reports must be submitted at the drop box in D2L for your lab section before the deadline. Monday’s lab report is due on the following Monday.

Late Report Policy: Only one late report will be accepted for full credit. All other late reports will not be graded. A late lab report is one passed the due date up until 5 PM on the third day after it was due (ie, if your lab report was due on Monday the late report will be due on the following Thursday by 5 pm at the drop box. Any report submitted after this date will not be graded.

Grading:

Each lab report is worth 20 points and the pre-lab quiz is worth 5 points. If an individual project is part of your lab curriculum, the project and presentation together are worth 50 pts total: 10 pts for a pre-lab assignment, 30 pts for report, and 10 pts for oral presentation).

The TAs will post the grades in D2L so that the students and the course instructor can have full access to it.

You must pass the lab with a 60% or better in order to pass the course.

LAB REPORTS

Your lab report must be grammatically correct and formatted according to this syllabus. Not following simple directions will result in a deduction of points. Unless otherwise stated, all lab reports must be typed! Reports must be written in third person and in past tense (ask me if you are unclear about this type of format). See the example I gave you. The grading rubric shown will be the one I grade off of every lab report (unless otherwise specified.)

Introduction (3 pts)

1. What was done? (Briefly explain the title)

2. Why was it done? (Purpose)

3. How was it done? (Name the technique(s)/ methods used)

4. Why should I care? (Practical applications)

Procedure and Observations (2 pts)

1. Length: 2-3 paragraphs of what was done and what was observed when you did it.

2. Sufficient details provided- experiment could be reproduced using write up.

3. Third person impersonal voice. Past tense!

4. This should be written in your own words! Do not plagiarize.

Data (2 pts)

1. The section should start with at least one sentence explaining what the data is/ where it came from. Data are not interpreted in this section! Data are solely shown and explained.

2. Tables of data / figures are clearly and correctly labeled including units and a caption.

3. Data should be reported with the correct sig figs.

4. Graphs should be incorporated into the report.

Data Analysis and Calculations (7 pts)

1. Include any relevant chemical formulas and sample calculations:

2. Calculations should be written step by step.

3. Appropriate units should be included.

4. If a theoretical value is provided (or if you can find a theoretical value online) you must calculate the percent error. Error ANALYSIS will be included in the conclusion.

5. A sample calculation is not needed when the weight of a substance is found (i.e. if you find the mass of a graduated cylinder, find the mass of the graduated cylinder with water, and subtract the values to determine the mass of the water.)

6. A unique equation number should be included. See the example provided.

7. Interpret your results for their meaning in the context of the experimental purpose

a. Outline the chemistry involved and tell me what you expected to see. Are the results what were expected?

Conclusion (6 pts)

1. Restate the purpose of the experiment

2. Was the purpose achieved? Why do you think it was or was not?

3. Discuss what the data mean and draw conclusions, include the following information.

a. Compare your results to the known value. Error should be reported numerically, including percent error when applicable.

b. If the results are not what were expected, outline possible sources of error that caused the results to be different. Include only possible and reasonable errors- human error is not a valid source. If your results are poor, discuss what you could do differently if you repeated the experiment.

4. Include any questions specifically asked for the report (in paragraph format).

5. The length of this section is variable depending on the experiment.

GRADING

Lab reports are due at the start of class the following week. Your report must also be submitted online through Dropbox (D2L) before class. You will get one free pass on a late report, which must be turned in no later than 3 days after the experiment was due. After this deadline passes, NO reports will be accepted. You WILL get a zero for every other late lab report.

Lab reports are worth 20 points; Pre-lab quiz are worth 5 points.

You must get a 60% or better in lab to pass the whole course.

If you are concerned about your writing style & knowledge of chemistry matching my grading style, please come and talk to me. I am more than happy to walk through old lab reports with you to show you how to fix errors. You cannot rewrite a lab report because you did poorly on it the first time- you can only improve on your future reports.

OTHER DETAILS

1) You must put on your safety goggles immediately after the pre-lab lecture or anytime chemicals are on lab benches. You may leave your goggles in your drawer, but then must IMMEDIATELY leave the lab. First time I catch you without goggles, you get a warning. Second time, you get a zero on that lab and kicked out. Third time, you will not be allowed to continue with lab.

2) Up to 5 points will be deducted from the report depending upon the cleanliness of the lab and your workstation.

MORE HINTS & GUIDELINES

Some rules for EVERY LAB REPORT you write:

1) Size 12, Times New Roman

2) Double spaced

3) Label equations, figures/graphs, tables, and include appropriate caption

4) Bold & capitalize headers

5) Cite your references!

6) The top of your report should be written in the following way (centered):

TITLE OF THE EXPERIMENT

CHMY 141-0XX

TA:

**/**/15

7) Do NOT write your name on the front of a handout lab report. On the back of your report, you will handwrite (or type) your name and your lab partner’s name.

1. Reports should be written using complete sentences. You should always use past tense, third person, and passive voice. You should never write the procedure in an “instructional” manner.

Correct: The reaction mixture was treated with...

Incorrect: I treated the reaction mixture with...

Incorrect: Treat the product with...

2. The introduction/procedure should tell what you did. Not what “will be done.”

Correct: The boiling point was determined with the thermistor.

Incorrect: The boiling point will be determined using the thermistor.

3. Do not use contractions (won’t, don’t, can’t).

4. Label all equations. You do not need to put a caption on equations.

Incorrect: Eqn 1: C4H8N2O2- + OH- ( C4H7N2O2- + H2O

Correct:

C4H8N2O2- + OH- ( C4H7N2O2- + H2O (1)

5. Word equations as well as a sample calculation should be used in one of your trial’s data.

Correct:

image1.emf
grams Ni2+ 1 mole Ni2+

molar mass Ni2+ moles Ni(DMG)2

moles Ni2+ =moles Ni(DMG)2

grams Ni

2+

1 mole Ni

2+

molar mass Ni

2+

moles Ni(DMG)

2

moles Ni

2+

=moles Ni(DMG)

2

(2a)
image2.emf
0.201g Ni2+ 1 mol Ni2+

59g Ni2+ 1 mol Ni(DMG)2

1 mol Ni2+ = 0.0034 mol Ni(DMG)2

0.201g Ni

2+

1 mol Ni

2+

59g Ni

2+

1 mol Ni(DMG)

2

1 mol Ni

2+

=0.0034 mol Ni(DMG)

2

(2b)
7. Include a caption for all tables and figures.

At end of document, in separate REFERENCES section:

1. Blazek, D. Loose Parts Comic, http://www.gocomics.com/looseparts/2012/07/30, retrieved 10 Jan. 2015.

I do not care what citation format you use as long as I can search for whatever you are citing and find it (online, library, etc.)

Correct:

Table 1: Data collected from the three trials of Ni(DMG)2 synthesis. The theoretical percent Ni2+ in nickel sulfate hexahydrate is 22.3%.

Trial

unknown Ni2+ compound (g)

Ni(DMG)2 (g)

Experimental

% Ni2+

Percent Error

1

0.210

0.267

25.8%

15.7%

2

0.205

0.242

23.9%

7.2%

3

0.198

0.254

26.1%

17.0%

Tone of the lab report should be formal, never include anything funny.

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