4. When copper chips are exposed to concentrated nitric acid, which gas is produced? a) Nitrogen (III) oxide b) Nitrogen (IV) oxide c) Nitrogen (I) oxide d) Nitrogen (II) oxide
Answer: b Explanation: The deadly brown gas, NO2, nitrogen (IV) oxide, is released when copper chips are treated with strong nitric acid. It’s a pungent-smelling reddish-brown gas.
