Question

In the laboratory a "coffee cup" calorimeter, or constant pressure calorimeter, is frequently used to determine the specific heat of a solid, or to measure the energy of a solution phase reaction. Since the cup itself can absorb energy, a separate experiment is needed to determine the heat capacity of the calorimeter. This is known as calibrating the calorimeter and the value determined is called the calorimeter constant. One way to do this is to use a common metal of known heat capacity. In the laboratory a student heats 97.50 grams of nickel to 97.64 °C and then drops it into a cup containing 83.67 grams of water at 21.42 °C. She measures the final temperature to be 29.78 °C. Using the accepted value for the specific heat of nickel (See the References tool), calculate the calorimeter constant.

Calorimeter Constant =  J/°C.

Answer 1

1-Energy given up by hot nickel=mass of nickel *specific heat*temperature change=q1=97.5*67.86*0.44=2911.194J (Specific heat of ni=0.44J/g•C) (Temperature diffrence=97.64-29.78=67.86•C)

2-Energy absorbed=q2=mass of Ni* specific heat of Ni*temperature change during process of absorption of heat= 97.5*0.44*(29.78-21.42)=358.644J

3-Diffrence between heat(which is basically absorbed by calorimeter) =q1-q2=2911.194-358.644=2552.55J

4-calorimetric constant=Heat absorbed by calorimeter/temperature change during absorption =2552.55/8.36=305.32J/•C