Class 11 Chemistry NCERT Solutions

Question 1.25

How are 0.50 mol Na₂CO₃ and 0.50 M Na₂CO₃ different?

Answer:

Molar mass of Na₂CO₃ = (2 × 23) + 12.00 + (3× 16)

= 106 g mol^–1

Now, 1 mole of Na₂CO₃ means 106 g of Na₂CO_3.

\ 0.5 mol of Na₂CO₃ 

= 53 g Na₂CO₃

∴ 0.50 M of Na₂CO₃ = 0.50 mol/L Na₂CO₃

Hence, 0.50 mol of Na₂CO₃ is present in 1 L of water or 53 g of Na₂CO₃ is present in 1 L of water.