Question

How are 0.50 mol Na2CO3 and 0.50 M Na2CO3 different?

Answer 1

Molar mass of Na2CO3 = (2 × 23) + 12.00 + (3 × 16) = 106 g mol-1
Now, 1 mole of Na2CO3 means 106 g of Na2CO3.
∴ 0.5 mol of Na2CO3 = $\frac {106\ g}{1 \ mole} × 0.5\ mol$ Na2CO3
= 53 g Na2CO3
⇒ 0.50 M of Na2CO3 = 0.50 mol/L Na2CO3

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