Answer:

A heat capacity problem.

Know that,

- Specific heat of water = 4.184 kJ/kg•°C

- when burning the naphthalene = (0.821 g)(40.1 kJ/g) = 32.92 kJ  

- temperature rise is 4.21°C  

- temperature in heating 1000 g of water from (4.21°C )( 4.184 kJ/kg•°C) = 17.61kJ  

- heat energy required in heating the calorimeter (32.92 kJ)-(17.61 kJ) = 15.31 kJ  

- Lastly, divide heat energy from heated calorimeter to the rise of temperature = 15.31/4.21  

- heat capacity of calorimeter = 3.635 kJ/°C

Explanation: