Question

What is the approximate molality of 10% (w/w) aqueous glucose solution? (Molar mass of glucose = 180 g mol\(^{-1}\))

• A. 0.31 m
• B. 0.62 m
• C. 0.93 m
• D. 1.24 m

Hint:

Molality is defined as the number of moles of solute per kilogram of solvent. To calculate, first find the moles of solute and divide by the mass of the solvent in kilograms.

Answer 1

The Correct Option is B

Molality (m) is calculated as: \[ m = \frac{\text{moles of solute}}{\text{mass of solvent in kg}} \] Given that we have 10% w/w glucose and the molar mass of glucose is 180 g/mol, we calculate the moles of glucose in 100 g of solution. Then, we calculate the molality using the mass of water as the solvent. The calculated molality is 0.62 m.