Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20238 AprilEvening Shift
Exam
JEE Main
Year
2023
Date
8 April
Shift
Evening Shift
Subject
Chemistry
Chapter
Solutions

JEE Main 2023 · 8 April · Evening Shift · Chemistry · Solutions

If the boiling points of two solvents X ~and Y (having same...

If the boiling points of two solvents XX~and YY (having same molecular weights) are in the ratio 2: 1\text{2: 1}~and their enthalpy of vaporizations are in the ratio 1:21: 2, then the boiling point elevation constant of XX is mm times the boiling point elevation constant of YY. The value of mm is (nearest integer).

Correct answer

0

Step-by-step solution

The boiling point elevation constant (Kb)\left({K}_{b}\right) of a volatile liquid is given by the following expression
Kb=RTb2MΔHv{K}_{b} = \dfrac{{RT}_{b}^{2}M}{{\Delta H}_{v}}

Where Tb={T}_{b} =boiling point of the liquid
M=M =molar mass of the liquid
ΔHv={\Delta H}_{v} = Enthalpy of vaporisation

The boiling points of the two solvents are in the ratio 2:12: 1, which means that the boiling point elevation constants are also in the ratio 2:12: 1. Let's call the boiling point elevation constant of solvent XX as (Tb)x( {T}_{b}{)}_{x}, and the boiling point elevation constant of solvent YYas (Tb)y( {T}_{b}{)}_{y}.
Given: Mx=My{M}_{x} = {M}_{y}
(Tb)x=2(Tb)y{\left({T}_{b}\right)}_{x} = 2{\left({T}_{b}\right)}_{y}
2(ΔHv)x=(ΔHv)y2\left({\Delta H}_{v}\right)x = {\left({\Delta H}_{v}\right)}_{y}
∴(Kb)x(Kb)y=(21)2×21=81=m∴ \dfrac{{\left({K}_{b}\right)}_{x}}{{\left({K}_{b}\right)}_{y}} = {\left(\dfrac{2}{1}\right)}^{2} \times \dfrac{2}{1} = \dfrac{8}{1} = m
∴m=8∴ m = 8

Therefore, the value of m is 88(nearest integer).

Practice Solutions on Quantrex Academy →

More from Solutions

In a solvent S , a compound B is partially dissociated into C and D as given below: B… JEE Advanced 2026Passage: Two volatile liquids A and B form an ideal solution. Consider a 5 molal solution… JEE Advanced 2026Passage: Two volatile liquids A and B form an ideal solution. Consider a 5 molal solution… JEE Advanced 2026Given below are two statements: Given: Molar mass of C, H, O, Cl are 12, 1, 16 and 35.5 g… JEE Main 2026Which of the following statements are not correct? A. For water, magnitude of K_b is more… JEE Main 2026Given below are two statements : Statement I : H _2 O molecules move from the chamber 1… JEE Main 2026When 0.25 moles of a non-volatile, non-ionizable solute was dissolved in 1 mole of a… JEE Main 202620 g hemoglobin in a 1 L aqueous solution (A) at 300 K is separated from pure water by… JEE Main 2026 Full Solutions list All JEE Main PYQs