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

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.

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.