Question

The net ionic equation for formation of an aqueous solution of NiI2 accompanied by evolution of CO2 gas via mixing solid NiCO3 and aqueous hydriodic acid is __________.A) 2NiCO3 (s) + HI (aq) ® 2H2O (l) + CO2 (g) + 2Ni2+ (aq)B) NiCO3 (s) + I- (aq) ® 2H2O (l) + CO2 (g) + Ni2+ (aq) + HI (aq)C) NiCO3 (s) + 2H+ (aq) ® H2O (l) + CO2 (g) + Ni2+ (aq)D) NiCO3 (s) + 2HI (aq) ® 2H2O (l) + CO2 (g) + NiI2 (aq)E) NiCO3 (s) + 2HI (aq) ® H2O (l) + CO2 (g) + Ni2+ (aq) + 2I- (aq)

Answer 1

First you need to write out the original equation.

$NiCO_{3(s)}+ HI_{aq} ->NiI_{2(aq)}+CO_{2(g)}+H_2O_{(l)}$

It needs to be balanced, though, so after balancing it should look like this:

$NiCO_{3(s)}+ 2HI_{aq} ->NiI_{2(aq)}+CO_{2(g)}+H_2O_{(l)}$

The ionic equation would look like this. (Only aqueous solutions can be split up).

$NiCO_{3(s)}+ 2H^+_{aq}+2I^-_{aq} ->Ni^{2+}_{aq}+2I^-_{(aq)}+CO_{2(g)}+H_2O_{(l)}$

The net ionic equation only contains the products that are not aqueous. Therefore, the final net ionic equation should be:

$NiCO_{3(s)}+ 2H^+_{aq} ->Ni^{2+}_{aq}+CO_{2(g)}+H_2O_{(l)}$

So your answer is C.