Question

In one molal solution that contains 0.5 mole of a solute, there is

• A. 500 mL of solvent
• B. 500 g of solvent
• C. 100 mL of solvent
• D. 1000 g of solvent

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Molality ($m$) is a concentration unit defined as the number of moles of solute per kilogram of solvent.
Key Formula or Approach:
\[ \text{Molality } (m) = \frac{\text{moles of solute}}{\text{mass of solvent in kg}} \]
Step 2: Detailed Explanation:
Given:
Molality ($m$) = 1 molal (1 mol/kg)
Moles of solute = 0.5 mol
Let the mass of solvent be $w$ kg.
\[ 1 = \frac{0.5}{w} \]
\[ w = 0.5 \text{ kg} \]
Converting to grams:
\[ w = 0.5 \times 1000 = 500 \text{ g} \]
Step 3: Final Answer:
The solution contains 500 g of solvent.