Question

" 1. The heat capacity of a calorimeter and its contents is 3.60 kJ/°C. If 0.300 moles of substance X is burned< in the calorimeter and the temperature increases by 15.0°C, caiculate the molar heat of combustion of substance X."

Answer 1

The molar heat of combustion of substance X, obtained via the formula q = -C*ΔT/m and plugging in given values, is -180.0 kJ/mole, indicating an exothermic reaction.

Step-by-step explanation:

In this problem, the molar heat of combustion, or the amount of heat energy that is produced when one mole of a substance undergoes complete combustion, is being asked for. This value is calculated by multiplying the heat capacity of the calorimeter by the temperature increase, and then dividing by the number of moles. The formula used is q = -C*ΔT/m, where q is the molar heat of combustion, C is the heat capacity of the calorimeter, ΔT is the change in temperature, and m is the number of moles. Here, C = 3.60 kJ/°C, ΔT = 15.0°C, and m = 0.300 moles. When you plug these values into the formula, you get q = -3.60 kJ/°C * 15.0°C / 0.300 moles = -180.0 kJ/mole. Hence, the molar heat of combustion of substance X is -180.0 kJ/mole. The negative sign indicates an exothermic reaction, meaning heat is released during the combustion process.

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