Question

what gas is evolved when acid (h⁺) is added to either carbonate or bicarbonate ion, serving to identify both ions? a oxygen b hydrogen c nitrogen d carbon dioxide

Explanation:

When an acid (providing \( H^+ \)) reacts with carbonate (\( CO_3^{2 -} \)) or bicarbonate (\( HCO_3^ - \)) ions, the reaction produces carbon dioxide (\( CO_2 \)) gas. For example, the reaction of hydrochloric acid with sodium carbonate: \( 2HCl + Na_2CO_3
ightarrow 2NaCl + H_2O + CO_2 \uparrow \), and with sodium bicarbonate: \( HCl + NaHCO_3
ightarrow NaCl + H_2O + CO_2 \uparrow \). Oxygen, hydrogen, and nitrogen are not produced in these reactions.

Answer:

D. Carbon dioxide