A chemical compound has a molecular weight of 89.05 g/mole. 1.400 grams of this compound underwent complete combustion under constant pressure conditions in a special calorimeter. This calorimeter had a heat capacity of 2980 J °C.1 (Note that the calorimeter was made of a metal shell, a water "substitute" - a special oil, and a thermocouple). The temperature went up by 11.95 degrees. Required:
Calculate the molar heat of combustion of the compound.

Explanation:

Hello!

In this case, for such calorimetry problem, we can notice that the combustion of the compound releases the heat which causes the increase of the temperature by 11.95 °C, it means that we can write:

In such a way, we can compute the total released heat due to the combustion considering the calorimeter specific heat and the temperature raise:

Next, we compute the molar heat of combustion of the compound by dividing by the moles, considering 1.400 g were combusted:

Thus, we obtain:

Best regards!

the awnser is group 12