Answer: The enthalpy of combustion, per mole, of butane is -2657.4 kJ
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
Putting the values we get :
2 moles of butane releases heat = 5314.8 kJ
1 mole of butane release heat = 
Thus enthalpy of combustion per mole of butane is -2657.4 kJ
The correct answer is D.
Increasing the pressure shifts the position of equilibrium towards the side with fewer gas molecules.
One to one ratio
The formula of hydrochloric acid is HCl so there is one atomic of hydrogen and one atom of oxygen