Question

Assertion (A): All exothermic reactions are accompanied with evolution of heat and light.
Reason (R): Combination reactions may or may not be exothermic.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, and Reason (R) is not the correct explanation of Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

In an exothermic reaction, energy is released in the form of heat and light, but this is not the case for all reactions.

Answer 1

The Correct Option is D

Assertion (A) is incorrect as exothermic reactions do not always release both heat and light; some only release heat.
Reason (R) is correct; combination reactions can be either exothermic or not, based on the reaction environment. 
Thus, the correct response is option (4).