Question

A sample of iron having a mass of 93.3g is heated to 65.58OC is placed in 75.0g ofwater raising the temperature from 16.95 OC to 22.24 OC. Find the specific heatcapacity for this iron sample. The answer you find has had some lab errors due tohuman mistakes. Find your percent error for your work using %Error = [(Expected - Actual) / (Expected Yield)] x100

Answer 1

The heat gained or lost by a substance undergoing a change in temperature is:
Q = mCpΔT
The heat lost by the iron is equal to that gained by water. The Cp for water is 4.186 Joules/gram

75 x 4.186 x (22.24 - 16.95) = -93.3 x Cp x (22.24 - 65.58)
Cp = 0.411 J/g

The heat capacity of iron is 0.45 J/g

%Error = [(0.45 - 0.41) / 0.41] x 100
%Error = 9.76%