Calcium oxide and carbon dioxide combine to form calcium carbonate in the reversible reaction:

Question

CaO + CO2 ⇌ CaCO3

When the reaction is at dynamic equilibrium, which statement must be true?

(1 point)
Responses

The concentration of calcium carbonate is increasing.
The concentration of calcium carbonate is increasing.

The forward and reverse reactions have stopped.
The forward and reverse reactions have stopped.

Calcium carbonate and calcium oxide are formed at the same rate.
Calcium carbonate and calcium oxide are formed at the same rate.

The reaction has run out of carbon dioxide or calcium oxide.
The reaction has run out of carbon dioxide or calcium oxide.

Answer 1

In the context of the reversible reaction:

\[ \text{CaO} + \text{CO}_2 \rightleftharpoons \text{CaCO}_3 \]

when the reaction is at dynamic equilibrium, it is true that calcium carbonate and calcium oxide are formed at the same rate. This means that the rate of the forward reaction (formation of calcium carbonate from calcium oxide and carbon dioxide) equals the rate of the reverse reaction (decomposition of calcium carbonate back into calcium oxide and carbon dioxide).

Therefore, the correct statement is:

Calcium carbonate and calcium oxide are formed at the same rate.