bomb calorimeter is heat combustion

Bomb calorimeter and coffee-cup calorimeter. Both useful, however, the bomb calorimeter is better to use if you're measuring deltaH of a gas

bcoz of space in the calorimeter....

bomb calorimeter measures heat transfer at constant while the cup measures at constant pressure.

In conducting a calorimetric test using a bomb calorimeter, the substance or object to be studied is placed inside the combustion crucible and ignited. The resulting reaction usually occurs so quickly that it resembles the explosion of a bomb-hence, the name "bomb calorimeter."