Question

100 mL of a 10 % NaOH (w/v) solution is added to 100 mL of a 10 % HCl (w/v) solution. The nature of the resultant solution is:

• A. alkaline
• B. strongly alkaline
• C. acidic
• D. neutral

Answer 1

The correct option is C acidic

In each solution, 10 g of solute is present in 100 mL solution.
Number of moles of NaOH present in its 10% solution $=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{10}{40}=0.25$ mol
Number of moles of HCl present in its 10% solution = $\frac{\text{Given mass}}{\text{Molar mass}}=\frac{10}{36.5}=0.27$ mol
As the number of moles of HCl are more than NaOH, so the final solution will be acidic.