Graphing a heating curve for water lab answers

Final Report

Exercise 1

CHEM 181 DL1 States of Matter

My results remained fairly consistent and my values only ranged from 38-40 degrees Celsius

1. Describe your results f or the melting point of tetradecanol. Were your results consistent? What was the range of values?

As a substance melts, the bonds begin to lose their strength and in turn, the substance turns into a liquid.

2. Describe what occurs to the particles of a substance when the substance melts. Explain why this occurs.

In this experiment, tetradecanol is in a condensed phase when it is a solid/going into the liquid stage. This must be due to the fact that the molecules are really close together.

3. When performing this experiment, when is the tetradecanol in a condensed phase? Explain your answer.

Copyright 2019 - Hands-On Labs | http://holscience.com 2 / 11

Data Table 1: Melting Point of Tetradecanol

I do not think tetradecanol is a crystalline solid because those kinds of solids usually go back to their solid form, from liquid the liquid form, in a very long time. This is not what happened. I believe it is a amorphous solid because it went back to a solid almost immediately.

4. Based on your observations of tetradecanol when it reformed a solid af ter melt ing, does tetradecanol f orm a crystalline or amorphous solid? Explain the dif f erence between these two terms as part of your answer.

Melting and boiling points are very important to know. For example, in commercial industries, like when jewelry is made, it is beneficial to know the melting points of the metals so they will be able to melt, and form the metals not jewelry. In a scientific point of view, it is important to know for safety and hazardous reasons.

5. Give some examples of how it might be useful to know the melting or boiling points of a substance. T hink in terms of both scientif ic and commercial/industrial settings.

Sources in error could include reading the thermometer incorrectly, setting the experiment up incorrectly, or not allowing things to heat for the time allowed.

6. Describe any possible sources of error f or this exercise.

Copyright 2019 - Hands-On Labs | http://holscience.com 3 / 11

Exercise 2

Melting Point for Tetradecanol (°C)

Trial 1

Trial 2

Trial 3

Average of the 3 Trials

38

39

40

39

I have uploaded the curve

1. Using the temperature data recorded in Data Table 2, create a heating curve.

Plot time (minutes) on the x-axis (horizontal axis) and temperature (°C) on the y-axis (vertical axis). Connect the plotted points with a line.

Label the heating curve to show each phase of matter (solid, solid + liquid, liquid, liquid + gas).

Label the melting point and boiling point on the heating curve.

Save an image (jpeg or png) of the graph, or take a screenshot.

Upload your graph to the panel titled Graph 1: Heating Curve .

Note: An example heating curve is given in Figure 6 in the background information.

Copyright 2019 - Hands-On Labs | http://holscience.com 4 / 11

The curve keeps a positive slope until it reaches the 8-9 minute mark, and at that point it begins to flat line. The slope is the ice as it goes from the sold to liquid form and from a liquid to a boil and then to a gas. When the slope is zero it is vaporizing.

2. Are there parts of the curve with posit ive slopes and parts that are f lat (slope of zero)? What states of matter are present when the slope of the heating curve is posit ive and what states of matter are present when the slope is zero or close to zero?

Solid: constant shape and volume, Liquid: No constant shape but constant volume, Gas: no constant shape or volume

3. Describe the key characterist ics for the three states of matter.

The melting point is the temperature when the solid is completely turned into a liquid. The melting point of water is between 0-5 degrees Celsius.

4. Def ine the melting point. What was the observed melting point of water?

Boiling point is the temperature that is required to make a liquid start vaporizing or turning into a gas. The boiling point for water is 100 degrees Celsius

5. Def ine boiling point. What was the observed boiling point of water?

Copyright 2019 - Hands-On Labs | http://holscience.com 5 / 11

Data Table 2: Temperature and Observations for Heating Curve

This happens when the temperature reaches the boiling point and only increases maybe a few degrees, or none. This happened in the last 15 minutes and the energy was used to vaporize the water into gas.

6. What happens to heat energy when it is not increasing the temperature of the substance in the beaker? Use your heating curve to explain your answer.

The temperature was not perfectly constant. The temperature of the liquid increased until boiling 100 degrees Celsius.

7. Was temperature perfectly constant during your test while the water was melting and while it was boiling? Explain why or why not.

Altitude, accidentally adding more/not enough ice, incorrect reading of the thermometer.

8. T he published melting point of H O is 0°C, and the published boiling point is 100°C. Why may you have found dif f erent values?

2

I do think the IMF of rubbing alcohol are greater than water. I believe this because of the information provided

9. Use the following information to determine if the intermolecular f orces of isopropyl alcohol are greater or weaker than the intermolecular f orces of water. Explain your answer. T he melting point of isopropyl alcohol (rubbing alcohol, C H O) is about -90°C and the boiling point is about 82°C.

3 8

Time (Min) Temperature (°C)

Copyright 2019 - Hands-On Labs | http://holscience.com 6 / 11

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

0

6

9

15

30

55

72

90

99

100

100

100

100

100

100

100

100

100

100

100

Copyright 2019 - Hands-On Labs | http://holscience.com 7 / 11

20

21

22

23

24

25

26

27

28

29

30

Time (Min) Observations

0

1

2

3

4

5

6

7

101

102

101

100

100

101

101

100

101

101

100

Starting point

Starting to change form around 25 seconds

70 percent liquid

90 percent liquid

100 percent liquid

Bubbles beginning to form

slowly begin to bubbling

Copyright 2019 - Hands-On Labs | http://holscience.com 8 / 11

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

bubbling

Starting to boil really quickly

Beginning to steam

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Condensation and steam forming

Still boiling

Still boiling

Less water, a lot of steam

Less water, a lot of steam

Still Less water, a lot of steam

Copyright 2019 - Hands-On Labs | http://holscience.com 9 / 11

Graph 1: Heating Curve

Exercise 3

26

27

28

29

30

Condensation and steam

Condensation and steam

Condensation and steam

Liquid getting less and less, steam

Steam and condensation

Almost no liquid, steam

Copyright 2019 - Hands-On Labs | http://holscience.com 10 / 11

Data Table 3: Observations of Gas Reactions

Hydrogen gas was produced because there was a loud popping noise, an explosion

1. In this experiment, there were two possible identit ies for the gas produced: hydrogen or chlorine, which have quite dif f erent properties. Hydrogen is a colorless, odorless, f lammable gas. Chlorine gas is greenish yellow with a pungent, bleach-like odor and is non-f lammable. Use your observations to determine which gas was produced in this experiment.

The gas forced the water out and to the test tube, and the gas replaced the water

2. As gas moved into the pipet bulb, where did the water go?

The gas forced the water out and to the test tube, and the gas replaced the water

3. Explain why the production of a gas in this experiment is or is not dif f erent f rom the formation of water vapor in the heating curve experiment.

Copyright 2019 - Hands-On Labs | http://holscience.com 11 / 11

Chemicals Observations

HCl

Zn

HCl + Zn Reaction

Gas + Flame

Liquid, clear

Solid, gray, shiny

It bubbled at the bottom, the hydrochloric acid was still a clear liquid

It bubbled at the bottom, the hydrochloric acid was still a clear liquid