Ethanoic acid reacts with sodium carbonate to form alkane.

Ethanoic acid was added to sodium hydrogen carbonate solution and the gas evolved was tested with a burning splinter. The following observations were reported. The correct observation is:

If sodium carbonate is added to ethanoic acid, a gas is evolved with rapid bubbling. This gas is-

In which of the following test tubes, effervescence will be observed?

Some vinegar is dropped on solid sodium carbonate. Brisk effervescence takes place with the evolution of a colourless gas. The gas is

Which of the four test tubes containing the following chemicals shows the brisk effervescence when dilute acid was added to them?

(i) $\mathrm{KOH}$

(ii) ${\mathrm{NaHCO}}_3$

(iii) ${\mathrm{K}}_2{\mathrm{CO}}_3$

(iv) $\mathrm{NaCl}$