Question

Why is it important to determine the qcalorimeter before determining the qmetal?

Answer 1

In order to determine the heat absorbed or given by a metal it is important to determine the heat loss or gained by calorimeter

If we dip a hot metal piece in a calorimeter, it will lose energy which will be absorbed by calorimeter

The heat absorbed by calorimeter = heat loss by metal

the heat absorbed by calorimeter = heat capacity of calorimter X change in temperature

so we should have the value of heat absorbed by calorimeter which will be equal to the heat loss by metal

heat loss by metal = mass of metal X specific heat of metal X change in temperature

thus we can calculate the specific heat of metal.

Answer 2

To find the enthalpy change per mole of a substance A in a reaction between two substances A and B, the substances are added to a calorimeter and the initial and final temperatures (before the reaction started and after it has finished) are noted