Purpose: The purpose of this lab is to calculate the specific heat of

aluminum using calorimetry.

Background: The specific heat capacity of a substance is the amount of

energy required to raise the temperature of one gram of that substance 1˚C. The specific heat capacity of liquid water is 4.184J/g˚C. Mathematically, for systems at constant pressure, with no volume changes, q = mC∆T, where

q=change in heat contentC=specific heat constantM=mass of the substance

∆T=change in temperature

In this experiment, a known mass of a metal is mixed at a high temperature with a known mass of water at room temperature in a coffee-cup calorimeter. By measuring the initial temperature of each substance and the final temperature of the system, the specific heat of the metal can be determined. The formula used is:

qwater = -qmetal

mwaterCwater∆Twater = -mmetalCmetal∆Tmetal

Materials: 500mL beaker Hot plate Celsius thermometer Test tube, stopper, and

clamp Analytical balance Aluminum sample

3 Styrofoam cups Graduated cylinder Distilled water Calculator Blow dryer

Procedure:1) Fill a 500mL beaker about ¾ full of tap water, and heat the beaker

on the hot plate until the water is boiling. 2) Obtain a metal sample of aluminum, mass the sample using the

analytical balance, and record the measurement.3) Put the massed metal sample into a dry test tube. Clamp the test

tube in the beaker of boiling water, making sure that the test tube does not touch the bottom of the beaker. The water level in the beaker should be above the level of the metal in the test tube. Put the thermometer in the test tube through the stopper so that it makes maximum contact with the aluminum pieces.

4) Take a dry Styrofoam cup and place it in another. Cut the top of a 3rd

one to form the lid of the calorimeter. Insert the thermometer through the top of the “coffee-cup” calorimeter.

5) Mass 60.0g of water into the calorimeter, and record the temperature. This is the initial temperature of the water.

6) When the temperature of the aluminum pieces reaches above 90 degrees Celsius, carry out the following operation as quickly as possible:

a. Record the temperature of the aluminum. This is the Tinitial of the aluminum.

b. Dump the hot metal into the calorimeter.c. Record the maximum temperature reached. This is Tfinal for

both the water and the aluminum.7) Repeat steps 5-10 at least twice. The metal need not be reweighed,

but it must be thoroughly dried before reheating. Use the blow dryer. The calorimeter must be dried and a fresh 60.0mL of distilled water should be used each time. If the tap water level in the heating beaker drops below the level of the metal, add more tap water as required and continue to heat.

8) Dry the metal sample thoroughly and return it to its original location.9) Calculate the specific heat of the metal from each trial, and

subsequently the average specific heat of the metal.

Conclusion: The specific heat content of aluminum is 0.08J/g°