Chemistry, asked by th7i1ksarathrivekMa, 1 year ago

The density of 2M NaCl solution is 1.117 g ml-1. The molality of the solution is (A)1 m(B)1.5 m(C)1.8 m(D)2 m

Answers

Answered by sharinkhan
21
Molarity= 2M

Molar mass of NaCl= 58.5

M= mass of solute/ molar mass of solute x volume
mass = 2 x 58.5 
= 117g

density = 1.117 = mass/ volume 
mass = density x volume 
= 1.117 x 1000
= 1117 g

mass of solvent = mass of solution - mass of solute 
= 1117- 117
= 1000g

molarity (m) = mass of solute /molar mass of solute x mass of solvent 
= 117 x 1000/58.5 x 1000kg
= 2m


Answered by RomeliaThurston
8

Answer: The correct answer is Option D.

Explanation:

The equation which shows the relationship between density, molarity and molality is given by:

\frac{1}{m}=\frac{d}{M}-\frac{M_B}{1000}

where,

m = molality of the solution

M = molarity of the solution

d = Density of the solution

M_B = Molar mass of the solute i.e. NaCl

We are given:

d=1.117g/mL\\M=2M\\M_B=[23+35.5]=58.5g/mol

Putting values in above equation, we get:

\frac{1}{m}=\frac{1.117}{2}-\frac{58.5}{1000}\\\\m=2m

Hence, the correct answer is Option D.

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