Some Basic Concepts of Chemistry - Result Question 40 — JEE PYQ Chapterwise

Answer:

Correct Answer: 40. (8)

Solution:

41. PLAN This problem can be solved by using concept of conversion of molarity into molality. Molarity $=3.2 \mathrm{M}$ Let volume of solution $=1000 \mathrm{~mL}=$ Volume of solvent

$\text { Mass of solvent }=1000 \times 0.4=400 \mathrm{~g}$

Since, molarity of solution is 3.2 molar

$\begin{aligned} & \therefore \quad n_{\text {solute }}=3.2 \mathrm{~mol} \\ & \text { Molality }(m)=\frac{3.2}{400 / 1000}=8 \\ \end{aligned}$

Hence, correct integer is (8).