India Exam Junction
39. To prepare 0.1 Molar solution of NaOH, how much NaOH is to be dissolved in 1 litre of water:
40 gm
400 gm
4 gm
0.4 gm
Correct Answer :
4 gm
Solution
The formula to calculate the amount of solute required for a molar solution is:
Mass of solute (g) = Molarity (M) × Molar mass (g/mol) × Volume of solution (L)
- Molarity (M) = 0.1 M
- Molar mass = 40 g/mol
- Volume = 1 L
Mass of NaOH = 0.1 × 40 × 1 = 4 g
Thus, 4 g of NaOH is required to prepare 1 liter of a 0.1 M NaOH solution.