Question

How are 0.50 mol Na₂CO₃and 0.50 M Na₂CO₃ different?

Answer 1

Molar mass of Na₂CO₃ = (2×23)+12.00+(3×16) = 106 g mol^-1 

∴0.50 mol Na₂CO₃ means 0.50×106g = 53g 0.50 M Na₂CO₃ means 

0.50 mol of Na₂CO₃ i.e. 53g of Na₂CO₃ are present in 1litre of the solution.