Question

Calculate the molality of 12.5% w/w sulphuric acid?

• A. 1.45m
• B. 2.50m
• C. 3.15m
• D. 2.85m

Answer 1

The correct option is A

1.45m

12.5% w/w means 12.5 g in 100 g of solution.

Weight of solvent = 100 g – 12.5 g= 87.5 g. Number of moles of sulphuric acid = 12.5/ 98 =0.127 mol

So molality = 0.127x1000/87.5 = 1.45 m