Determining the Specific Heat Capacity of an Unknown Metal
(Lab Guidelines: 1,2,3,4,5&6[attach handout],7,9,11,12)
Purpose: To determine the identity of a piece of unknown metal by using Heat Gained = Heat Lost, and the equation Q=CmT to calculate the specific heat capacity of a metal.
Intro Info:
What is Specific Heat Cpacity?
What does Heat Gained = Heat Lost mean?
Materials: piece of unknown metal, Bunsen burner, ring stand ring clamp, wire gauze, 250 mL beaker, water, Styrofoam cup, crucible tongs, Temperature Probe
Procedure:
- Fill in the specific heat capacity of liquid water in your data table.
- Using the balance, RECORD the mass of the piece of metal.
- Carefully place the metal in an empty 250 mL beaker.
- Fill the beaker ¾ full of tap water.
- Set up ring stand, clamp, wire gauze and burner. Light burner.
- Bring beaker of water to a steady boil.
- Using the balance tare a Styrofoam cup and pour in about 100 grams of water. RECORD the exact mass of the water.
- One the water in the beaker is boiling steadily, use the temperature probe, to RECORD the temperature of the boiling water. We can assume that this is the initial temperature of the metal.
- Using the probe, now RECORD the temperature of the water in the Styrofoam cup. This is the initial temperature of the water in the cup.
- Using crucible tongs, transfer the piece of metal from the boiling water into the Styrofoam cup as quickly as possible. Stirthe water with the temperature probe until the temperature remains constant.
- RECORD the final temperature of the water. We can also assume that this is the final temperature of the metal.
- Make sure you have all values filled in for the data table below. There should be only one value that is not filled in yet. What is it??
Data Table: WHERE IS THE QUESTION MARK???
Water in Styrofoam Cup / MetalMass
Specific Heat Capacity
Initial Temperature
Final Temperature
Calculations:
- Using Q=CmT calculate the heat energy gained by the water.
- How much heat energy was lost by the metal?
- Based on the principle of Heat Gained = Heat Lost, use Q=CmT to calculate the specific heat capacity of the metal.
- Use the following specific heat capacity chart to identify the piece of metal. What is your metal.
Metal / Specific Heat (J/g*C)
Aluminum / 0.900
Copper / 0.385
Lead / 0.129
Iron / 0.449
Tin / 0.228
Zinc / 0.388
Error Analysis:Once given the identity of your metal and its specific heat capacity, calculate your percent error for the specific heat capacity of the metal. Discuss any sources of error that could have occurred.
Conclusion: Write a conclusion which demonstrates that you understand what you did. How did you accomplish the purpose? Discuss the math as well.
Explain how you used the idea of Heat Lost = Heat Gained to achieve your objective and complete your calculations.
Remember, here is a great guide for writing your conclusion:
1) Restate the purpose
2) Summarize the procedure and data collection
3) Discuss any important principles / equations used
4) Explain the graphs and/or math
5) Report your results
Also, please include any other interesting information you would like to add.