Final answer:
Different metals react with dilute acids in various ways; aluminum, zinc, and iron typically produce effervescence from the evolution of hydrogen gas, whereas copper shows no observable change (d).
Step-by-step explanation:
When aluminum, zinc, iron, and copper are separately reacted with dilute acids, different observations are noted. For aluminum, zinc, and iron, we typically see effervescence (bubbling) with the evolution of a gas such as hydrogen. When zinc metal is placed into copper sulfate, a redox reaction occurs, indicated by the zinc dissolving and the formation of copper as fine black particles instead of the characteristic reddish color.
Zinc and iron reacting with acid are both examples of gas forming reactions. When zinc reacts with hydrochloric acid, hydrogen gas is produced, marked by vigorous bubbling. Similarly, iron powder reacts rapidly with dilute hydrochloric acid producing hydrogen gas bubbles; however, an iron nail reacts more slowly due to less surface area being exposed to the acid.
For copper, no observable change is expected, as copper is less reactive than hydrogen and does not displace hydrogen from the acid. According to the Activity Series, copper does not react with dilute acids to produce hydrogen gas. In summary, we classify the reactions of zinc and aluminum with acid as gas forming, the reaction of zinc with copper sulfate as a redox reaction, and there is no observable change for copper with dilute acids.