Question

HELP PLEASE

Answer 1

Answer: Option (A) is the correct answer.

Explanation:

A chemical reaction where heat energy is absorbed by the reactant molecules is known as an endothermic reaction.  

For example, $A + B + Heat \rightarrow AB$

The value of $\Delta H$ = +ve for an endothermic reaction.

In an endothermic reaction, more heat is absorbed by the chemical bonds for the breakdown as compared to the heat released.

On the other hand, a chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.

For example, $C + D \rightarrow CD + Heat$ is an exothermic reaction.

Thus, we can conclude that endothermic reaction is the type of reaction which is represented by A.

Answer 2

Answer:

A is an endothermic reaction.

Explanation:

When energy of breaking bonds is greater than the energy released during making of bonds, we need to supply energy to the reaction and thus the reaction is called as endothermic reaction. We can also say that the enthalpy of formation of products is more than the enthalpy of formation of reactants making overall enthalpy change to be positive.

While in case B, the energy to break bond is less than the energy released during making of bonds. thus there is overall released of energy during the reaction and hence it is exothermic reaction.