1

Name: ________________________________________________________ Date: ___________________

Chemistry Lab Mr. Zamojski

Q1 – Heating Curve of H2O PRE-LAB ASSIGNMENT

Required Safety Data Sheets (SDS): NONE

Required Pre-Lab Video: ZamJ713 channel on YouTube: “Quarter 1 Chemistry Lab – Heating Curve of

H2O”

QUESTIONS: Refer to the information from the pre-lab video to answer the questions below.

States of Matter:

1) What state of matter is ice? ___________________________

2) What state of matter is water? ___________________________

3) What state of matter is steam? ___________________________

Phase Changes

4) Draw 4 particles of water as ice. Show the vibrations of the particles in your drawing.

5) Draw 4 particles of water as liquid water. Show the motion of the particles in your drawing.

6) Draw 4 particles of water as steam. Show the motion

of the particles in your drawing.

7) What is the melting/freezing point of water? __________°F = __________°C = ___________ K

8) What is the boiling/condensing point of water? __________°F = __________°C = ___________ K

Equipment Safety & Setup:

9) What piece of safety equipment should you wear for this lab? ________________________

10) What description of clothing is not allowed for this lab? ______________________________

2

11) What piece of safety equipment is optional for this lab? ______________________________

12) What piece of equipment will you use for heating? ______________________________

13) What equipment will you use to prevent being burned by hot glassware?

__________________________ or _______________________________

14) What piece of glassware will you use to contain the ice and water? ______________________________

15) What tool will you use to measure temperature? ______________________________

16) What piece of equipment will serve as your heating platform? ______________________________

17) What two options do you have for setting up your heating station?

___________________________ or ________________________________________________________

Doing the Lab

18) Do you want a tall or short flame when your Bunsen burner is lit? _____________________

19) After placing the thermometer in the beaker of ice water, should you take the temperature immediately

or wait a few moments as the liquid level in the thermometer stabilizes? ________________

20) Should the gas valve under your lab station be pointed to the side or down? __________________

21) What precaution should you take just in case you accidently knock over your Bunsen burner?

_______________________________________________________________________________________

22) Which direction should you turn the valve underneath the Bunsen burner to OPEN and CLOSE it?

Clockwise/right = __________________________ Counterclockwise/left = ________________

23) List the proper sequence for lighting a Bunsen burner.

a. FIRST ____________________________________________________________

b. THEN ____________________________________________________________

24) List the 4 symptoms you may experience if you breathe in too much natural gas.

a. ___________________________________________________________

b. ___________________________________________________________

c. ___________________________________________________________

d. ___________________________________________________________

3

25) What should you do if you feel any of these symptoms in the lab?

______________________________________________________________________________________

26) At which time should you record your first temperature reading in the DATA TABLE? ____________

27) How often should you record the temperature of the ice-water mixture? ________________________

28) What should you do with your thermometer before each temperature reading? __________________

29) What evidence from the beaker indicates that boiling is occurring? ________________________

30) What evidence from the beaker indicates that the water has reached its boiling point?

__________________________________________________________________________________________

31) You should continue recording temperature measurements each minute until

___________________________________________________________________________________

Clean Up:

32) What is the clean up procedure for this lab?

a. _________________________________________________

b. ______________________________________________________________________________

c. Use _______________ or _____________________________________ to take beaker off of the

stand

d. ______________________________________________________________________________

to avoid getting accidently burned

After Completing Measurements & Clean Up:

33) How should you label your horizontal axis (x-axis)? _________________________________

34) How should you label your vertical axis (y-axis)? _________________________________

4

Name: _____________________________________________________ Date: _________________

Partner(s): ____________________________________

Chemistry Lab Mr. Zamojski

Q1 – Heating Curve of H2O LAB PROCEDURE

Background:

In this lab you will observe the phase changes of water from solid to liquid to gas. The temperature at which the solid to liquid phase change occurs is called the melting point. The temperature at which the liquid to gas

phase change occurs is called the boiling point.

Melting Point of Water = 0.0°C = 273.0 K

Boiling Point of Water = 100.0°C = 373.0 K

Purpose:

You will perform measurements to determine if there is a relationship between the temperature of an ice-water-steam mixture and the time as the sample is heated. In particular, you will pay attention to the temperature and

time at the melting point and boiling point of water.

LAB GRADE

Your grade for this lab will be based on the following criteria:

• Using the proper safety equipment (goggles)

• Following procedures and staying on task at your lab station

• Following safe practices and properly handling accidents

• Cleaning up your lab station

• Completing the lab report

Materials:

ice water

ring stand or tripod

Bunsen burner thermometer

wire mesh

beaker goggles

tongs or rubber holder

Heating Ice-Water Mixture

Procedure:

1) Put your goggles on.

2) Obtain a beaker. Add a small amount of water and some ice to the beaker.

3) Place the beaker of water on your wire mesh on your ring stand or metal tripod.

5

4) Place a thermometer in the beaker of ice water.

5) Record the temperature in DATA TABLE at 0 minutes. Also record any observations.

6) Ignite your Bunsen burner. Set your flame to a small blue flame.

7) Record the temperature of the ice-water system every minute in the DATA TABLE. Record any notable

changes or observations as well.

a. If there is still ice in your container, stir the ice for 5 seconds before reading the temperature.

b. Do not change the flame height unless your instructor tells you to. If you do have to change the

flame height, then indicate this change in DATA TABLE in the observation section.

8) Once you have reached the boiling point for water, check with your instructor. Your instructor will

determine if you need any additional data points.

Clean Up: A) Turn off the gas, so that your Bunsen burner flame goes out.

B) Pick up the thermometer using the end farthest away from the beaker, and return it to your

instructor.

C) Pick up the beaker of water using tongs or rubber holders. Pour out the water into the sink,

and place the beaker on the drying rack by the sink.

D) Carefully take any hot metal equipment to the designated area to cool.

E) Return your goggles to the goggles cabinet.

ANALYSIS:

Using the information in DATA TABLE, make a scatterplot on a separate sheet of graph paper.

The graph should be titled “Heating Curve for Water” with Time (min) on the x-axis and Temperature (°C)

on the y-axis. Use an appropriate scale for each axis. Plot your data from the DATA TABLE, but do not

connect the data points. Use the template below page as a guide.

0102030405060708090

100

0 5 10 15 20 25 30 35 40

Tem

per

atu

re (

°C)

Time (min)

Heating Curve for Water

6

Name: ________________________________________ Date: ___________________

Partner(s): ___________________________________________

DATA TABLE

Time Temperature

(°C)

Changes or Notable Observations

0 min

1 min

2 min

3 min

4 min

5 min

6 min

7 min

8 min

9 min

10 min

11 min

12 min

13 min

14 min

15 min

16 min

17 min

18 min

19 min

20 min

7

Time Temperature

(°C)

Changes or Notable Observations

21 min

22 min

23 min

24 min

25 min

26 min

27 min

28 min

29 min

30 min

31 min

32 min

33 min

34 min

35 min

36 min

37 min

38 min

39 min

40 min

8

Chemistry Laboratory Write-up Checklist

Your lab write-up is due by FRIDAY, NOVEMBER 3, 2017.

Experiment: Heating Curve of H2O Name _______

Safety,

Procedures,

& Cleanup

(4 points)

1. Used goggles

2. Followed procedures and stayed on task

3. Followed safe practices

4. Cleaned up lab station prior to leaving

Purpose and

Design (2 points)

1. What were you trying to learn in this lab?

2. Briefly describe the procedure you used.

Data & Evaluation

(10 points)

Include the following: 1. Completed DATA TABLE

2. Graph of your temperature vs. time graph for the heating

of water

3. Your graph is labeled

(A) low temperature plateau

(B) a region of temperature change

(C) high temperature plateau

Conclusion

(9 points)

1. System questions.

2. Describe regions of the graph

3. Rate of heating question.

4. Percent Error Calculations

Maximum Score = 25 points Your score: _________

9

Name: ________________________ Lab: Heating Curve of H2O

PURPOSE:

In this lab I performed measurements to determine if there was a relationship between

______________________________ of an ice-water-steam mixture and the ______________ as the sample is

heated. In particular, I paid attention to the temperature and time at the ______________________________

and ______________________________________ of water.

EXPERIMENTAL DESIGN:

In this experiment I took a sample of ice water and made an initial observation. Then I ignited a Bunsen burner,

and every minute I measured the temperature using a ___________________________. The experiment was

complete when the solid-liquid phase change has occurred, which is called _________________________, and

the liquid-gas phase change has occurred, which is called ______________________________.

DATA & EVALUATION:

Complete your scatterplot of temperature vs. time for your measurements. Make sure to include a graph title, x-axis title, y-axis title, and an appropriate scale on each axis. Do not connect the data points!

Then divide your heating curve into three regions; label each region:

(1) a low temperature plateau (relatively flat slope) (2) a region of temperature change (steeper slope)

(3) a high temperature plateau (relatively flat slope)

** Attach your DATA TABLE and your scatterplot of your heating curve on graph paper.

CONCLUSIONS:

1. a) Did the H2O molecules undergo a physical change or a chemical change as the sample transitioned from solid to liquid to gas? Explain.

(Hint: A physical change does not change the identity of the particles although the arrangement of the particles may be different. A chemical change results in new particles with a different identity than the

original particles.)

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

10

b) Did the ice-water-steam system in the beaker absorb or release energy? Explain.

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

2. Fill in the table below using your temperature vs. time graph and the three regions you labeled.

Low Temperature

Plateau

Region of

Temperature Change

High Temperature

Plateau

Was the energy being supplied

by the flame causing faster

particle motion (rapidly

increasing temperature) or a

change in configuration of

the particles (small or no increase in temperature)?

What phases of matter were

present in this region?

Draw a model at the particle

level that shows how water particles were behaving. Use 9

particles.

3. How would increasing the rate of heating at the start of the experiment affect the shape of your graph?

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

11

4. Percent Error is a calculation used to determine how accurate the results of your experiment are by

comparing the measurements or values you obtained to the accepted measurement or value. The following

equation is used.

𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝐸𝑟𝑟𝑜𝑟 = 𝑀𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑉𝑎𝑙𝑢𝑒 − 𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑉𝑎𝑙𝑢𝑒

𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑉𝑎𝑙𝑢𝑒 × 100%

When using the percent error equation, do not be concerned if you get a negative number. This is acceptable.

• If your percent error is positive, this means that your measured value is greater than the accepted value.

• If your percent error is negative, this means that your measured value is less than the accepted value.

Using your best estimate from your data and your graph determine the melting point of ice. This will be your

measured value. My measured value for the melting point of ice is ___________________________________.

Using the equation above calculate the percent error for the melting point. Convert temperatures to Kelvin.

Accepted Value for Melting Point of Ice = 273.0 K (0.0°C)

Show Your Work Here:

Percent Error for Melting Point = ___________________________________

Using your best estimate from your data and your graph determine the boiling point of water. This will be

your measured value. My measured value for the boiling point of water is _____________________________.

Using the equation above calculate the percent error for the boiling point. Convert temperatures to Kelvin.

Accepted Value for Boiling Point of Water = 373.0 K (100.0°C)

Show Your Work Here:

Percent Error for Boiling Point = ___________________________________

12

• If a percent error is within 10% (–10% < percent error < 10%), the results are considered reasonably

accurate.

o This is acceptable accuracy for a high school chemistry lab.

• If your percent error is greater than 10% or less than –10%, then the results are not considered accurate.

At this point you need to determine what your sources of error and whether the errors are personal (lack of care

and precision in completing measurements) or systematic (there is something wrong with a measuring tool or

with the procedure used).

a) Based on the calculations you have completed are your measured melting and boiling points reasonably

accurate? ___________________

b) If they are reasonably accurate explain what you did during the experiment ensure good results. If they

are not reasonably accurate, propose sources of error, either personal or systematic, that you think

contributed to the less accurate results.

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________