Treating ammonium ions with sodium hydroxide produces a gas that turns damp red litmus blue. What gas is produced?

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Multiple Choice

Treating ammonium ions with sodium hydroxide produces a gas that turns damp red litmus blue. What gas is produced?

Explanation:
When a weak acid in the form of ammonium ion meets a strong base, a gas that behaves as a base is produced. Here, ammonium ion reacts with hydroxide from sodium hydroxide to give ammonia gas and water: NH4+ + OH- → NH3 + H2O. The ammonia dissolves in water to form ammonium hydroxide, which raises the pH and makes damp red litmus paper turn blue. This basic gas is the key clue. Hydrogen gas would not turn red litmus blue, oxygen is not formed in this reaction, and carbon dioxide is acidic and would not produce a blue colour change.

When a weak acid in the form of ammonium ion meets a strong base, a gas that behaves as a base is produced. Here, ammonium ion reacts with hydroxide from sodium hydroxide to give ammonia gas and water: NH4+ + OH- → NH3 + H2O. The ammonia dissolves in water to form ammonium hydroxide, which raises the pH and makes damp red litmus paper turn blue. This basic gas is the key clue.

Hydrogen gas would not turn red litmus blue, oxygen is not formed in this reaction, and carbon dioxide is acidic and would not produce a blue colour change.

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