The combustion of butane in oxygen at 298 K is given by the following thermochemical equation:
2 C₄H₁₀ (g) + 13 O₂ → 8 CO₂ (g) + 10 H₂O (l) $\Delta_{T} H_{298}^{\theta}$ = -2878 kJ mol^-1. How much heat energy (in kJ) is supplied when 775 g of butane burn in a plentiful supply of air so that combustion is complete?

Question

The combustion of butane in oxygen at 298 K is given by the following thermochemical equation:
2 C₄H₁₀ (g) + 13 O₂ → 8 CO₂ (g) + 10 H₂O (l)

\Delta_{T} H_{298}^{\theta}

= -2878 kJ mol^-1. How much heat energy (in kJ) is supplied when 775 g of butane burn in a plentiful supply of air so that combustion is complete?

Quizplus · Accepted Answer

The heat energy supplied when 775 g of butane burn is:$$Q = - \Delta_{T} H_{298}^{	heta} 	imes n$$$$n = \frac{775 g}{58 g/mol} = 13.36 mol$$$$Q = - (-2878 kJ/mol) 	imes 13.36 mol = 38370 kJ$$

The Combustion of Butane in Oxygen at 298 K Is ΔTH298θ\Delta_{T} H_{298}^{\theta}ΔT​H298θ​

The Combustion of Butane in Oxygen at 298 K Is $\Delta_{T} H_{298}^{\theta}$