Question

When 8.5 g of methane (ch4) is burned in a bomb calorimeter (heat capacity = 2.677 × 103 j/°c), the temperature rises from 24.00 to 27.08°c. how much heat is absorbed by the calorimeter?ch4(g) + 2o2(g) → co2(g) + 2h2o(l); ∆h° = –1283.8 kj?

Answer 1

The molar mass of methane is 16 g/mol. The heat absorbed by the calorimeter is the sensible heat, which is the heat gained or lost during a temperature change.

Sensible heat = CΔT = (2.677 kJ/°C)(27.08 - 24°C)
Sensible heat = 8.24 kJ

Answer 2

Answer is: 8.24 kJ of heat is absorbed by the calorimeter.

ΔT= 27.08°C - 24.00°C.

ΔT = 3.08°C; temperature change of reaction.

m = 8.5 g; mass of methane.

cp= 2.677 kJ/°C, specific heat capacity of the bomb calorimeter.  

Qcal = ΔT(methane) · cp(methane).  

Qcal = 3.08°C · 2.677 kJ/°C.  

Qcal = 8.245 kJ; amount of heat absorbed.