Acids, Bases and Salts NCERT Solution, study material, CBSE Notes

NCERT Solution: Acids, Bases and Salts

How is the concentration of hydronium ions (H3O+) affected when a solution of an acid is diluted?

When an acid is diluted, the concentration of hydronium ions (H₃O⁺) per unit volume decreases. This means that the strength of the acid decreases.

How is the concentration of hydroxide ions (OH−) affected when excess base is dissolved in a solution of sodium hydroxide?

The concentration of hydroxide ions (OH⁻) would increase when excess base is dissolved in a solution of sodium hydroxide.

You have two solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of this is acidic and which one is basic?

A pH value of less than 7 indicates an acidic solution, while greater than 7 indicates a basic solution. Therefore, the solution with pH = 6 is acidic and has more hydrogen ion concentration than the solution of pH = 8 which is basic.

What effect does the concentration of H+ (aq) ions have on the nature of the solution?

If the concentration of H⁺ (aq) ions is increased (>10-7) then the solution become acidic and if the concentration of H⁺ (aq) ions is decreased (<10-7) then the solution become basic in nature.

Do basic solutions also have H+ (aq) ions? If yes, then why are these basic?

Yes, basic solution also has H⁺ ions. However, their concentration is less as compared to the concentration of OH^– ions that makes the solution basic.

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

If the soil is acidic and improper for cultivation, then to increase the basicity of soil, the farmer would treat the soil with quick lime or slaked lime or chalk.

What is the common name of the compound CaOCl2?

Bleaching Powder

Name the substance which on treatment with chlorine yields bleaching powder?

Calcium hydroxide [Ca(OH)₂], on treatment with chlorine, yields bleaching powder.