Question

What is the molality of an aqueous solution containing 6 % glucose by mass ? ( Molar mass of glucose = 180 g/mol )

• A. \(0.15\) m
• B. \(0.25\) m
• C. \(0.35\) m
• D. \(0.45\) m

Hint:

Take 100 g of solution: 6 g glucose and 94 g water, then divide moles by kilograms of water.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Molality \(m=\dfrac{\text{moles of solute}}{\text{mass of solvent in kg}}\).

Step 2: Take 100 g of solution
Glucose \(=6\text{ g}\) and water \(=100-6=94\text{ g}=0.094\text{ kg}\).

Step 3: Moles of glucose
\(\dfrac{6}{180}=0.0333\text{ mol}\).

Step 4: Calculation
\(m=\dfrac{0.0333}{0.094}\approx0.35\text{ m}\).

Final Answer:
The molality is about 0.35 m. \[ \boxed{\text{(C) }0.35\text{ m}} \]