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 .

NiCO3 (s) + 2H+ (aq) → H2O (l) + CO2 (g) + Ni2+ (aq)

Explanation:

To write the complete ionic equation:

1. Start with a balanced molecular equation.

2. Break all soluble strong electrolytes (compounds with (aq) beside them) into their ions

3. indicate the correct formula and charge of each ion

4. indicate the correct number of each ion

5. write (aq) after each ion

6. Bring down all compounds with (s), (l), or (g) unchanged.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

it is the most commonly accepted one