Question

Calculate amount of sodiumcarbonate needed to prepare 0.5 M and 0.1M

solutions in 250 mL volumetric flask.​

Answer 1

Explanation:

Molarity = No. of moles of solute/ Volume of solution in litres

Molar mass of Na2CO3 is 106 g

0.1 M = wt./ 106/0.25 L

Wt. = 0.1 M x 106 g/mol x 0.25 L = 2.65 g

0.5 M = wt./ 106/ 0.25 L

Wt. = 0.5 M x 106 g/mol x 0.25 L = 13.25 g