Repeated use of which one of the following fertilizers would increase the acidity of the soil?

Options

A. potassium nitrate
B. Urea
C. Superphosphate of lime
D. Ammonium sulphate

Answer

4

Explanation

Becauase ammonium sulphate a sallt of weak base `(NH_(3))` and strong acid `(H_(2)SO_(4))` undergoes hydrolysis to yield an acidic solution.
Superhosphate is a mixture of calcium tetrahydrogen diorthoposhphate and calcium sulphate made by treating mineral phosphate with concentrated sulphiric acid:
`Ca_(3)(PO_(4))_(2)+2H_(2)SO_(4)rarr underbrace(Ca(H_(2)PO_(4))_(2)+2CaSO_(4))_("Superphosphate")`
The diphosphate salt is more soluble than untreated mineral phosphates and is therefore more easily assimilated by plants. An improved product is obtained by treating mineral phosphate with orthophosphoric acid instead of sulphuric acid:
`Ca_(3)(PO_(4))_(2)+4H_(3)PO_(4) rarr 3Ca(H_(2)PO_(4))_(2)`
This fertilixers called tripke superphosphate because its phosphate content is about three times that of ordinary superphosphate fertilizer is preferred because it lowers fright costs: