The heat of combustion of a substance is :

Question

The heat of combustion of a substance is : (A) Always positive (B) Always negative (C) Numerically equal to the heat of formation (D) Unpredictable

Tardigrade Admin · Accepted Answer

Heat of combustion of a substance is always negative as it is the amount of heat evolved (i.e. decrease in enthalpy) when one mole of the substance is completely burnt in air or oxygen.

Q. The heat of combustion of a substance is :

Always positive

Always negative

Numerically equal to the heat of formation

Unpredictable

Heat of combustion of a substance is always negative as it is the amount of heat evolved (i.e. decrease in enthalpy) when one mole of the substance is completely burnt in air or oxygen.