Ncert Exercises & Solutions

Select the correct option based on statements given below:

Assertion (A):	Combustion of all organic compounds is an exothermic reaction.
Reason (R):	The enthalpies of all elements in their standard state are zero.

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.

Hint: Combustion is an exothermic reaction

Combustion of organic compounds is always exothermic. Heat or enthalpy of formation of natural elements in their standard

the state is considered to be zero. Hence, both assertion and reason are true and the reason is not the correct explanation of

assertion.