A farmer finds that the soil has a pH of 5. What should be added to reduce the soil’s acidity for better crop growth?
Answer and explanation
Correct answer: Calcium hydroxide
The pH scale shows that a value below 7 is acidic; therefore, pH 5 indicates acidic soil. To reduce acidity, a suitable base is added so that neutralisation occurs and the pH rises. Calcium hydroxide is a basic compound and can neutralise excess acids in soil, so option C is correct. Hydrochloric acid would increase acidity, while ammonium chloride is an acidic salt. Sodium chloride is essentially neutral and is not the appropriate corrective material.
Frequently asked questions
What is the correct answer to this question?
Calcium hydroxide
Why is this the correct answer?
The pH scale shows that a value below 7 is acidic; therefore, pH 5 indicates acidic soil. To reduce acidity, a suitable base is added so that neutralisation occurs and the pH rises. Calcium hydroxide is a basic compound and can neutralise excess acids in soil, so option C is correct. Hydrochloric acid would increase acidity, while ammonium chloride is an acidic salt. Sodium chloride is essentially neutral and is not the appropriate corrective material.
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.
