Chapter U4.21, Problem 7E

Interpretation Introduction

Interpretation: The substance which can be used to neutralize the lake damaged by acid rain needs to be determined.

Concept Introduction: The reaction between an acid and a base is a neutralization reaction. Thus, acidic solutions are neutralized by basic solutions and basic solutions are neutralized by acidic solutions.

Answer to Problem 7E

Correct answer: Option (d) is correct.

Explanation of Solution

Reason for correct option: Acid rain is acidic in nature because of the presence of acidic substances like nitric acid and sulfuric acid.

To neutralize the acidic water of acid rain, basic substance is required therefore ${\text{Ca(OH)}}_{\text{2}}$ must be used as it is a strong base and it can neutralize acidic substance present in the acid rain.

Conclusion

Reasons for incorrect options: ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ and ${\text{CH}}_{\text{3}}\text{COOH}$ are acidic substances so they cannot neutralize acid rain water. ${\text{CaCl}}_{\text{2}}$ is the salt of strong acid HCl and strong base ${\text{Ca(OH)}}_{\text{2}}$ so it is neutral salt and cannot be used to neutralize acid rain.