Question

10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of a given solution of HCl. If we take 20 mL of the same solution of NaOH, the amount of HCl solution (the same solution as before) required to neutralise it will be:

विकल्प

• 4 mL

• 8 mL

• 12 mL

• 16 mL

Answer 1

16 mL

Explanation:

Since the concentrations of both the sodium hydroxide (NaOH) and hydrochloric acid (HCl) solutions remain unchanged, the volume of acid required for complete neutralisation is directly proportional to the volume of the base.

The initial neutralisation reaction shows that 10 mL of NaOH gives 8 mL of HCl.

When the volume of the NaOH solution is increased to 20 mL, it is exactly twice the original volume.

Scaling factor = `20/10`

= 2 mL

To maintain the neutralisation balance, the required volume of the HCl solution must also be multiplied by this same factor:

Required HCl = 8 × 2

= 16 mL