Question

1. will the concentration of naoh solution increase or decrease if the solution is exposed to air for prolonged periods? briefly explain.

Explanation:

NaOH (sodium hydroxide) is a base. When NaOH solution is exposed to air, it reacts with carbon dioxide (CO₂) present in the air. The reaction is \(2NaOH + CO_2=Na_2CO_3 + H_2O\). In this reaction, the amount of NaOH (the solute) decreases as it reacts to form sodium carbonate and water. Concentration of a solution is defined as the amount of solute per unit volume of solution (\(Concentration=\frac{Amount\ of\ Solute}{Volume\ of\ Solution}\)). Since the amount of solute (NaOH) decreases while the volume of the solution may remain approximately the same (or even increase slightly due to absorption of water from air, but the main factor is the consumption of NaOH), the concentration of the NaOH solution will decrease.

Answer:

The concentration of the NaOH solution will decrease. This is because NaOH reacts with carbon dioxide in the air (\(2NaOH + CO_2 = Na_2CO_3 + H_2O\)), reducing the amount of NaOH (solute), and as concentration depends on solute amount per solution volume, the concentration decreases.