Question

Most economical and effective method of control of soil pH is application of

• A. $CaC{O}_3$
• B. $CaC{I}_2$
• C. $Ca(N{O}_3{)}_2$
• D. $Ca(OH{)}_2$

Answer 1

The correct option is A $CaC{O}_3$

$\text{Soil pH and role of calcium carbonate}$

The values on the pH scale range from $0$ to $14$. Values less than $7$ are acidic and above $7$ are alkaline.

Acidic soil is treated by adding calcium carbonate $\left(CaC{O}_3\right)$ to neutralise the acidity and balance the pH.

The dissolution of lime in the soil causes the calcium $\left(Ca\right)$ to move to the surface of soil particles. Meanwhile the abundant hydrogen ions react with the carbonate ions (liberated from lime) to form carbon dioxide $\left(C{O}_2\right)$ and water $\left(H_{2}O\right)$. This makes the soil less acidic.

Final answer
(a) $CaC{O}_3$