Chemistry · THERMODYNAMICS

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Combustion reactions of hydrocarbons are invariably exothermic in nature. Reason (R): The standard enthalpy of combustion (\( \Delta_c H^\ominus \)) is defined as the enthalpy change accompanying the complete combustion of one mole of a substance in presence of excess oxygen. In the light of the above statements, choose the correct answer from the options given below:

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.