Question

A student takes a small quantity of Sodium hydrogencarbonate powder in a dry test tube and pours 4-5 drops of Ethanoic acid over it. What will he observe?

• A. Evolution of a colourless gas with pungent smell
• B. Bubbles of a colourless and odourless gas
• C. Evolution of brown fumes along with a brisk effervescence
• D. Evolution of a colourless gas which burns with a pop sound when a burning splinter is brought near it

Answer 1

The correct option is B

Bubbles of a colourless and odourless gas

The explanation for the correct option:

B: Bubbles of a colourless and odourless gas

• When Ethanoic acid reacts with metal carbonates and hydrogen carbonates, it produces Carbon dioxide, salt, and water.
• When Ethanoic acid reacts with Sodium bicarbonate or Sodium hydrogen carbonate, Sodium acetate, and bubbles of a colourless and odourless gas Carbon dioxide is formed as shown in the reaction below.$$\begin{gathered} {\mathrm{CH}}_3\mathrm{COOH}\left(\mathrm{l}\right)+{\mathrm{NaHCO}}_3\left(\mathrm{s}\right)\to {\mathrm{CH}}_3\mathrm{COONa}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right) \\ \mathrm{Ethanoic}\mathrm{Sodium}\mathrm{Sodium} \\ \mathrm{acid}\mathrm{hydrogencarbonate}\mathrm{acetate} \end{gathered}$$
• Therefore, option B is correct. Sodium Hydrogen carbonate reacts with Ethanoic acid to form bubbles of a colourless and odourless gas.