Question

this passage describes a chemical reaction. read the passage. then, answer the question below. people have used silver (ag) throughout history to make jewelry and silverware. silver items are valued for their shiny appearance, but over time, they can become dull. the dullness comes from a layer of tarnish that gradually forms on the surface of silver items. tarnish, which is made of silver sulfide (ag₂s), forms when silver combines with hydrogen sulfide (h₂s) from the air. fortunately, you can remove tarnish by polishing silver. in the chemical reaction described in the passage, which of the following are reactants? select all that apply. silver (ag) silver sulfide (ag₂s) hydrogen sulfide (h₂s)

Explanation:

To determine reactants, we recall that reactants are substances that undergo a chemical reaction to form products. The passage states: "Tarnish, which is made of silver sulfide ($\ce{Ag_{2}S}$), forms when silver combines with hydrogen sulfide ($\ce{H_{2}S}$ from the air." So silver ($\ce{Ag}$) and hydrogen sulfide ($\ce{H_{2}S}$) are the reactants that combine to form silver sulfide ($\ce{Ag_{2}S}$, the product, or tarnish). Silver sulfide is the product, not a reactant. So the correct reactants are silver ($\ce{Ag}$) and hydrogen sulfide ($\ce{H_{2}S}$).

Answer:

• silver (Ag)
• hydrogen sulfide ($\ce{H_{2}S}$)