Which changes increase the rate of reaction between calcium

hydrochloric acid?

carbonate and dilute

1

2

3

increasing the concentration of the acid

increasing the temperature

increasing the size of the pieces of calcium carbonate

1. Increasing the concentration of the acid

2. Increasing the temperature

Explanation:

CaCO₃ + 2HCl ⟶ CaCl₂ + H₂O + CO₂

Increasing the concentration of the acid increases the number of hydronium ions in contact with the surface of the CaCO₃ per unit time.

Increasing the temperature increases the kinetic energy of the hydronium ions, so they hit the surface of the CaCO₃ mor frequently and with greater force.

3. is wrong. The bigger the pieces, the smaller the surface area that is available for reaction.