Chapter U5, Problem 3STP

Interpretation Introduction

Interpretation:

The correct name for the following reaction needs to be identified

${\text{NaHCO}}_{\text{3 }}\text{+ HCl}\to {\text{NaCl + H}}_{\text{2}}{\text{CO}}_{\text{3}}$

Concept introduction:

Chemical reactions in general involve an exchange of heat between the system (reactants and products) and the surroundings.

An endothermic process involves absorption of heat by the system from the surroundings, whereas an exothermic process involves liberation of heat by the system to the surroundings.

Answer to Problem 3STP

(B) Exothermic

Explanation of Solution

The given reaction is:

${\text{NaHCO}}_{\text{3 }}\text{+ HCl}\to {\text{NaCl + H}}_{\text{2}}{\text{CO}}_{\text{3}}$

Here, the system is the beaker containing the above reactants and products. It is mentioned that the temperature inside the beaker drops from 24°C to 17°C. This suggests that energy is released by the system to the surroundings. Since the reaction is accompanied by a release of energy, it is termed as an exothermic reaction.

Conclusion

The reaction between sodium bicarbonate and hydrochloric acid is an exothermic reaction