Question

518 g of an aqueous solution contains 18 g of glucose. What is the molality of the solution?

• A. 0.1 m
• B. 0.5 m
• C. 0.2 m
• D. 0.9 m

Answer 1

The correct option is C 0.2 m

$\text{Molality}=\frac{\text{number of moles of solute}}{\text{total mass of the solvent in g}}\times 1000$

$\text{Moles of solute (Glucose)}=\frac{18}{180}=0.1mol$

$\text{Amount of solvent present}=518–18g=500g$

$\text{Molality}=\frac{0.1}{500}\times 1000=0.2m$