The density of 3M solution of NaCl is 1 . 0g mL ^ - 1 . Molality of the solution is ______ × 10 ^ - 2 m (Nearest integer). Given: Molar mass of Na and Cl is 23 and 35 . 5g mol ^ - 1 respectively.

Correct answer: 0 Formula unit mass of sodium chloride = 23 + 35 . 5 gmol ^ - 1 = 58 . 5 gmol ^ - 1 ∴ m ( molality ) = 1000 × M 1000 × d - M × M . Wof solute ... ( M = Molarityofsolution ) = (1000 × 3)/(1000 × 1 - ( 3 × 58 . 5 )) = 3 . 64 = 364 × 10 ^ - 2

JEE Main 20231 FebruaryMorning Shift

Exam: JEE Main
Year: 2023
Date: 1 February
Shift: Morning Shift
Subject: Chemistry
Chapter: Some Basic Concepts of Chemistry

JEE Main 2023 · 1 February · Morning Shift · Chemistry · Some Basic Concepts of Chemistry

The density of 3M solution of NaCl is 1 . 0g mL ^ - 1 . Molality of...

The density of $3M$ solution of $NaCl$ is $1 . 0g{mL}^{- 1}$ . Molality of the solution is $______ \times {10}^{- 2}m$ (Nearest integer).

Given: Molar mass of $Na$ and $Cl$ is $23$ and $35 . 5g$ ${mol}^{- 1}$ respectively.

Correct answer

Step-by-step solution

Formula unit mass of sodium chloride = $23 + 35 . 5{gmol}^{- 1} = 58 . 5{gmol}^{- 1}$
$∴ m ( molality ) = \dfrac{1000 \times M}{1000 \times d - M \times M . W\text{of solute}}$ ... $( M = Molarityofsolution )$

$= \dfrac{1000 \times 3}{1000 \times 1 - ( 3 \times 58 . 5 )} = 3 . 64$

$= 364 \times {10}^{- 2}$

Practice Some Basic Concepts of Chemistry on Quantrex Academy →

More from Some Basic Concepts of Chemistry

Match List-I with List-II. List-I Mass of substance List-II Number of atoms A. 1.8 mg… JEE Main 2026 Which of the following contain the same number of atoms ? (Given : Molar mass in g mol ^… JEE Main 2026 An oxide of iron contains 69.9\% iron, its empirical formula, is: (Given: Molar mass of… JEE Main 2026 What volume of hydrogen gas at STP would be liberated by action of 50 mL of H_2SO_4 of… JEE Main 2026 How many grams of residue is obtained by heating 2.76 g of silver carbonate? (Given… JEE Main 2026 The correct order of total number of atoms present in (A) 2 moles of cyclohexane (B) 684… JEE Main 2026 Number of moles and number of molecules in 1.4187 L of SO_2 at STP respectively are: JEE Main 2026 The ratio of mass percentage (w/w) of C : H in a hydrocarbon is 12 : 1 . It has two… JEE Main 2026 Full Some Basic Concepts of Chemistry list All JEE Main PYQs