Question

Under what soil conditions do you think a farmer would treat the soil of his fields with quicklime (calcium oxide), or slaked lime (calcium hydroxide) or chalk (calcium carbonate)?

Answer 1

Calcium oxide, calcium hydroxide, and calcium carbonate are all bases (pH > 7); hence, they must be used only when the soil is too acidic (pH < 7). They help neutralise soil acidity and bring the pH closer to 7.