Question

Hydrogen chloride gas is collected by_______________.

Answer 1

Collection of Hydrogen chloride gas:

• Hydrogen chloride is an acidic, colourless gas that can be easily identified based on its unique odour.
• The high solubility of hydrochloric acid in water makes it difficult to collect the gas through the downward displacement water technique.
• The gas is produced by a reaction between sodium chloride and concentrated sulphuric acid and acidic and collected using a technique called downward delivery (Upward displacement of air).
• The reaction for the above process is given by;

$\underset{\mathrm{Sodium}\mathrm{chloride}}{2\mathrm{NaCl}\left(\mathrm{s}\right)}+\underset{\mathrm{Sulphuric}\mathrm{acid}}{\mathrm{conc}.{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)}\to \underset{\mathrm{Hydrochloric}\mathrm{acid}}{2\mathrm{HCl}\left(\mathrm{g}\right)}\left(\mathrm{fumes}\right)+\underset{\mathrm{Sodium}\mathrm{sulphate}}{{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{s}\right)}$

• The less-dense gas expands and moves, the denser air sinks, and this method of gas preparation is called the upward delivery or displacement method.
• The gas being $$1.28$$ times heavier than air is best collected through this method.

Hence, the Hydrogen chloride gas is collected by upward displacement of air.