A student adds dilute hydrochloric acid to a white solid and observes vigorous bubbling. The gas produced turns limewater milky. Which anion is present in the solid?

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Question

A student adds dilute hydrochloric acid to a white solid and observes vigorous bubbling. The gas produced turns limewater milky. Which anion is present in the solid?

Accepted Answer

Carbonate ion (CO₃²⁻) — Carbonate ions react with dilute hydrochloric acid to produce carbon dioxide gas, which causes effervescence and turns limewater milky. Sulfate, chloride, and hydroxide ions do not produce a gas that turns limewater milky under these conditions.

Answer

Sulfate ion (SO₄²⁻)

Answer

Carbonate ion (CO₃²⁻)

Answer

Chloride ion (Cl⁻)

Answer

Hydroxide ion (OH⁻)

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