Which substance should a farmer add to acidic soil to reduce its acidity?
Answer and explanation
Correct answer: Slaked lime, Ca(OH)₂
The governing concept is neutralisation: an acidic substance is treated with a suitable base. Slaked lime, Ca(OH)₂, supplies hydroxide ions that react with excess hydrogen ions in acidic soil, reducing its acidity. In simplified form, H⁺ + OH⁻ → H₂O. Dilute hydrochloric acid and carbon dioxide would add to acidity, while sodium chloride is essentially neutral and is not the appropriate corrective material. Thus option A is correct.
Frequently asked questions
What is the correct answer to this question?
Slaked lime, Ca(OH)₂
Why is this the correct answer?
The governing concept is neutralisation: an acidic substance is treated with a suitable base. Slaked lime, Ca(OH)₂, supplies hydroxide ions that react with excess hydrogen ions in acidic soil, reducing its acidity. In simplified form, H⁺ + OH⁻ → H₂O. Dilute hydrochloric acid and carbon dioxide would add to acidity, while sodium chloride is essentially neutral and is not the appropriate corrective material. Thus option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
