Question

copper carbonate (cuco₃) reacts with hydrochloric acid (hcl) according to this equation:
cuco₃(s) + 2hcl(aq) → cucl₂(aq) + h₂o(l) + co₂(g).
which statement correctly describes the substances in this reaction?

a. exactly one product and two reactants are either liquid or dissolved in water.

b. exactly one of the reactants is in a water-based solution, but none of the products are.

c. the reactants include both a liquid and a gas.

d. exactly one reactant is a solid, and exactly one product is a gas.

e. the products include a solid, a liquid, and a gas.

Explanation:

Let's analyze each option by examining the states of reactants and products from the equation $\ce{CuCO_{3}(s) + 2HCl(aq) -> CuCl_{2}(aq) + H_{2}O(l) + CO_{2}(g)}$:

• Option A: Reactants: $\ce{CuCO_{3}(s)}$ (solid), $\ce{HCl(aq)}$ (aqueous, dissolved in water). Products: $\ce{CuCl_{2}(aq)}$ (aqueous), $\ce{H_{2}O(l)}$ (liquid), $\ce{CO_{2}(g)}$ (gas). So reactants with liquid/aqueous: 1 reactant ($\ce{HCl}$) and products with liquid/aqueous: 2 ($\ce{CuCl_{2}}$, $\ce{H_{2}O}$). So A is wrong.
• Option B: Reactant $\ce{HCl}$ is aqueous (water - based solution). Products: $\ce{CuCl_{2}(aq)}$ (aqueous) and $\ce{H_{2}O(l)}$ (liquid) are in water - related states. So B is wrong.
• Option C: Reactants: $\ce{CuCO_{3}(s)}$ (solid) and $\ce{HCl(aq)}$ (aqueous). No liquid or gas reactant. So C is wrong.
• Option D: Reactant $\ce{CuCO_{3}}$ is solid (exactly one reactant is solid). Product $\ce{CO_{2}}$ is gas (exactly one product is gas). This matches.
• Option E: Products: $\ce{CuCl_{2}(aq)}$ (aqueous), $\ce{H_{2}O(l)}$ (liquid), $\ce{CO_{2}(g)}$ (gas). No solid product. So E is wrong.

Answer:

D. Exactly one reactant is a solid, and exactly one product is a gas.