Which four metals are not reactive enough to react with acids?

• A. Copper, Silver, Gold, Platinum
• B. Copper, Iron, Zinc, Aluminum
• C. Tin, Lead, Mercury, Cadmium
• D. Iron, Copper, Aluminum, Magnesium

Answer: (A)

The main idea is how metals react with acids based on their place in the reactivity series. Metals that are more reactive than hydrogen will push hydrogen out of acids, releasing hydrogen gas. Metals that are less reactive than hydrogen won’t displace hydrogen from acids under normal conditions, so no hydrogen gas is produced.

The metals that are less reactive than hydrogen are copper, silver, gold, and platinum. Because they sit below hydrogen in the reactivity sequence, they don’t react with common acids like dilute hydrochloric or sulfuric acid to release hydrogen gas. They can be surprisingly resistant and only react with very strong or oxidizing acids under special conditions, which is why they are considered not reactive enough to react with acids in typical tests.

In contrast, metals such as iron, zinc, aluminum, and magnesium are above hydrogen in the series, so they readily react with acids to form hydrogen gas and metal salt. That’s why those metals aren’t the correct set for “not reactive enough to react with acids.”