Question

Marble and chalk or two forms of calcium carbonate. Equal masses of marble lumps and powdered Chalk are added to dilute hydrochloric acid.

The marble takes longer than the chalk to fully react. Why is this so?

(a) marble is more reactive than chalk

(b) marble is more soluble than Chalk

(c) The Marble has the smaller surface area than chalk.

(d) The marble is more basic than chalk.

Answer 1

(c) The Marble has the smaller surface area than chalk.

Chalk reacts faster, bеcause it has far more surface area per unit weight than marble chips.

Surface area is important in chemical kinetics. Increasing the surface area of a substance (for example by powdering generally increases the rate of a chemical reaction.