Question

Assign the reason for the following observation:

If a bottle full of Concentrated sulphuric acid is left open in the atmosphere by accident, the acid starts flowing out on its own.

Answer 1

Hygroscopic substances: A hygroscopic substance is one that readily attracts water from its surroundings.

Example: Honey, Ethanol, Methanol, Concentrated sulfuric acid, etc.

Concentrated Sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ starts flowing out of the open bottle on its own because:

1. $\mathrm{Concentration}\propto \frac{1}{\mathrm{Volume}}$
2. As the volume of a solution increases its concentration decreases and solution becomes dilute.
3. Concentrated sulfuric acid is highly hygroscopic in nature.
4. It absorbs moisture from the atmospheric air due to which its volume get increases and which in turn leads to the dilution of concentrated sulfuric acid.

Therefore, as the volume of sulfuric acid increases due to its hygroscopic nature, it starts flowing out of the bottle.