Question

The pH of soil $A$ is $7.5$ while that of soil $B$ is $4.5$. Which of the two soils should be treated with powdered chalk to adjust its pH and why?

Answer 1

Soil $B$ having pH $4.5$ should be treated with powdered chalk to adjust its pH. Because soil $B$ is too acidic and its acidity can be reduced by adding powdered chalk $\left(Ca{CO}_3\right)$, which is a base.