Question

The acidity of soil, which is due to excessive use of ______________ can be neutralized by adding lime.
A. Fertilizer ammonium sulphate
B. Caustic soda
C. Washing soda
D. None of these

Answer 1

The soil $pH$ is the determination of acidity or basicity of soil. In order to neutralize the acidic soil we have to add acid in it. In the above question soil is neutralized by adding the base that is lime.

Complete step by step answer:
Soil $pH$ is considered a master variable in soils as it affects many chemical processes. It specifically affects plant nutrient availability by controlling the chemical forms of the different nutrients and influencing the chemical reactions they undergo. The optimum $pH$ range for most plants is between $5.5 - 7.5$ however, many plants have adapted to thrive at $pH$ values outside this range.
In order to solve the above question, in the option A:
Fertilizer ammonium sulphate, it is acidic in nature if the soil is acidic in nature then it is neutralized by adding some base to it that is lime or calcium oxide.
Hence, option A is correct.
In the option B:
Caustic soda is a base and that’s why it is basic in nature so this will be neutralized by adding acid to it. So it cannot be neutralized by adding lime.
Hence, option B is incorrect.
Washing soda is a base and that’s why it is basic in nature so this will be neutralized by adding acid to it. So it cannot be neutralized by adding lime.
Hence, option C is incorrect.
So, The acidity of soil, which is due to excessive use of fertilizer ammonium sulphate can be neutralized by adding lime.

So, the correct answer is Option A.

Note: At room temperature ${25^0}C$ , solutions which have $pH$ less than $7$ are acidic in nature and solutions which have $pH$ greater than $7$ are basic in nature. Solutions which have $pH$ exactly equal to $7$ at room temperature are neutral in nature for example water. The neutral value of the $pH$ depends on the temperature, being lower than $7$ if the temperature increases. The $pH$ value can be less than $0$ for very strong acids, or greater than $14$ for very strong bases.