SNC2D – Weather Unit

Heat Capacity Lab: Heat Capacity of Water vs. Land

Purpose: to determine the heat capacity of land and compare that to the heat capacity of water.

Hypothesis:

Materials:

Graduated cylinder, beaker, tongs, 1 rock, thermometer, 4 styrofoam cups.

At front of room:

Hot plate, metal cooking pot, rocks and an electronic balance.

Safety:

  1. Goggles at all times.
  2. Do not touch the hot metal pot on the hot plate.
  3. Do not attempt to carry the hot rock with your bare hands.
  4. Notify the teacher immediately if you break any glassware.

Procedure:

  1. Measure 50 mL of water into a styrofoam cup. Stack two cups so that one sits inside the other. Make sure you do not use the one with the hole in the bottom! The third cup with the hole will be the lid later on.
  2. Measure the initial temperature of the water using the thermometer and record it on your chart.
  3. Obtain a rock from the boiling water at the side bench. Use the tongs to remove 1 rock and place it in the fourthstyrofoam cup (not the one with the hole!). Do not walk across the room with the rock in your tongs!
  4. Place the hot rock in your cup full of water.
  5. Quickly cover the cup with your third cup. Stick the thermometer through and wait.
  6. Once the temperature stops increasing (you may have to open the lid to check this), record the final temperature in your observations.
  7. Wait for the temperature to return down close to the initial temperature.
  8. Remove the rock and determine its mass using the electronic balance.
  9. Determine the heat capacity for the rock.

Note: Assume that your final temperature is the same for both the water and the rock.

Observations:

Mass of Water (in kilograms)
Assume 1 mL = 1 g
Heat Capacity of Water / 4200 J/kg °C
Initial Temperature of Water C
Final temperature of styrofoam cup containing rock (water).
Temperature change of water.
Mass of rock
Initial temperature of rock from hot water bath. / 100 °C
Final temperature of styrofoam cup containing rock (rock).
Temperature change of rock.

Discussion Questions:

  1. Explain the term “heat capacity”.
  1. Calculate the heat capacity for the rock.

Remember, heat lost by one substance MUST be gained by something else.

Therefore Qrock = mcΔT

Qwater = mcΔT

Where heat lost by the rock (Qrock) equals the heat gained by the water (Qwater)

Hint:

Use the formula below:

(mass rock)(heat capacity rock)(temperature change rock) =

(mass water)(heat capacity water)(temperature change of water)

(mrock)(Crock)( ΔTrock)=(mwater)(Cwater)( ΔTwater)

Heat Capacity for Rock:

  1. If the heat capacity of water is 4200 J/Kg°C, which substance; water or rock has a higher heat capacity?
  1. If 1 Kg of water is cooled 1 °C, how much energy is released?
  1. If 1 Kg of your rock is cooled 1 °C how much energy is released?
  1. How much of the Earth is covered by land? (you will need to look this up)
  1. How much of the Earth is covered by water? (you will need to look this up)
  1. Describe why the prairies have cold winters, but British Columbia has warm winters.
  1. Explain why England has cool summers and warm winters.

Conclusion:

List and describe three sources of error for this lab. Remember error is something you did in the lab or something you used that could lead to inaccuracies in your results. You must explain WHY and HOW this type of error could make your results incorrect.

Lab Report : Heat Capacity of Water vs. Land

Teacher Name: Ms. Houghton
Student Name: ______
CATEGORY / 4 / 3 / 2 / 1
Components of the report / All required elements are present and additional elements that add to the report (e.g., thoughtful comments, graphics) have been added. / All required elements are present. / One required element is missing, but additional elements that add to the report (e.g., thoughtful comments, graphics) have been added. / Several required elements are missing.
Data / Professional looking and accurate representation of the data. Data contains all units. / Accurate representation of the data but data is messy and/or difficult to read and/or missing units. / Accurate representation of the data in written form, but some are in accurate or incomplete. / Data are not shown.
Calculations / All calculations are shown and the results are correct and labeled appropriately. / Some calculations are shown and the results are correct and labeled appropriately. / Some calculations are shown and the results labeled appropriately. / No calculations are shown OR results are inaccurate or mislabeled.
Discussion / All questions are answered completely and correctly. / All questions are answered and are accurate, understanding is demonstrated, but some are vague or contain inaccuracies. / All questions are answered but only satisfactory understanding is demonstrated. or Not all questions are answered, but the ones answered are accurate. / Most questions are unanswered or all questions are answered incorrectly.