Question

which of the following is the correct word equation for the reaction described below? calcium hydroxide and hydrogen gas are produced by the reaction of calcium hydride and water. calcium hydride + hydrogen → calcium hydroxide + water calcium hydride + water → calcium hydroxide + hydrogen calcium hydroxide + hydrogen → calcium hydride + water calcium hydroxide + water → calcium hydride + hydrogen

Explanation:

To determine the correct word equation, we analyze the reaction description: reactants are calcium hydride and water, products are calcium hydroxide and hydrogen gas. The word equation should have reactants on the left of the arrow and products on the right.

• First option: Reactants are calcium hydride and hydrogen (incorrect, hydrogen is a product), products are calcium hydroxide and water (incorrect, water is a reactant).
• Second option: Reactants are calcium hydride and water (matches the description), products are calcium hydroxide and hydrogen (matches the description).
• Third option: Reactants are calcium hydroxide and hydrogen (incorrect, these are products), products are calcium hydride and water (incorrect, these are reactants).
• Fourth option: Reactants are calcium hydroxide and water (incorrect, these are product and reactant mix), products are calcium hydride and hydrogen (incorrect, calcium hydride is a reactant).

Answer:

B. calcium hydride + water → calcium hydroxide + hydrogen