Question

Calculate the mass of sodium acetate required to make 500 ml of 0.375 molar aqueous solution consider the molar mass of sodium acetate is 82

Answer 1

0.375 M aqueous solution of sodium acetate

≡ 1000 mL of solution containing 0.375 moles of sodium acetate

∴Number of moles of sodium acetate in 500 mL

 

Molar mass of sodium acetate = 82.0245 g mole–1 (Given)

∴ Required mass of sodium acetate = (82.0245 g mol–1) (0.1875 mole)

= 15.38 g

Answer 2

molarity = mass of solute per litre / Atomic mass of solute

Given,

Atomic mass of CH3COONa = 82.0245g/mol

molarity = 0.375

Therefore, mass of solute per litre = 0.375x82.0245

= 30.759

=> To make 500ml of same molarity = 30.759/2 = 15.38g