Heat Energy Calculation Lab
Introduction
Heat is a form of energy. Heat energy is used to heat buildings (our school) and run motors (cars). In this lab you will be calculating the amount of solar energy (heat) used to raise the temperature of water.
Objective
The student will:
1. determine how much energy is used to raise the temperature of the water.
2. use the unit of joules to measure energy
3. correlate differences in joules used to heat the water at various temperatures
4. correlate differences in joules used to heat various amounts of water
Materials
250 ml beakers. Thermometers, graduated cylinders, watch
Procedure
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1. Obtain a group number from your teacher.
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2. Fill your beaker to the desired amount of water and temperature according to your assigned group number below.
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3. Answer the Pre-lab questions on the following page.
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4. Place the filled beaker with water in direct sun for 30 minutes.
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5. After 30 minutes take the beaker of water out of the sun and answer the post-lab questions.
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6. Calculate the amount of heat energy added to raise the temperature of the water with the formula below.
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7. Fill in the class table with your information under your group number. The other groups will fill in their information under their group number and we will compare our results with the completed class table.
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8. Answer the Conclusion questions.
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Group 1 100ml H2O cold water
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Group 2 100 ml H2O at room temp water
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Group 3 100ml H2O in hot water
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Group 4 100ml H2O at room temp
Group 5 200ml H2O at room temp
Group 6 300ml H2O at room temp
Formula: Q = mc /_\ t
Heat
(Joules)
= mass x specific heat x change in temp.
Q = heat in Joules added
c = specific heat = 4.184 J/g °K = specific heat of water
m = mass of water
/_\ t = final temperature – initial temperature
Variables to be studied
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1. Same Mass Different Temperature
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2. Different Mass Same Temperature
Pre-Laboratory Questions
1. Before we go outside
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1. Measure initial volume_________________
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2. Measure initial temperature_____________
2. What is the variable for groups 1-3 ______________________________.
Group 1 100ml H2O cold water
Group 2 100 ml H2O at room temp water
Group 3 100ml H2O in hot water
3. What is the variable for groups 4-6________________________________.
Group 4 100ml H2O at room temp
Group 5 200ml H2O at room temp
Group 6 300ml H2O at room temp
Data Tables
Variable 1_______________________________________________________________
Title:
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Group Mass
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Specific Heat
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/_\ temp Joules
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1.
2.
3.
Variable 2_______________________________________________________________
Title:
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Group Mass
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Specific Heat
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/_\ temp Joules
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4.
5.
6.
Post-Laboratory Questions
After we return
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1. measure final volume___________________
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2. measure final temperature_______________
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3. Calculate the amount of heat energy used to raise the temperature of the water for your group.
Formula: Q = mc /_\ t
Conclusions
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1. Discuss your differences in volume. What caused this difference
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2. What is the phase change which is occurring for this difference to take place?
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3. Discuss the idea of heat in relation to its formula
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4. Draw a conclusion on the correlation between mass, temperature and heat from the class results.
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