PractifyUs

NEET Chemistry · Solutions

Concentration of solutions

Taught in NCERT Class 12 Chemistry, Chapter 1: Solutions.

1 verified question: Easy 0 · Medium 1 · NEET level 0

Sample questions

Sample 1Medium

A solution of ethylene glycol (C2H6O2) in water is 20% by mass. What is the mole fraction of ethylene glycol? (Molar masses: C2H6O2 = 62 g mol^-1, H2O = 18 g mol^-1)

  1. A

    0.25

  2. B

    0.20

  3. C

    0.932

  4. D

    0.068

Show the answer
The answer is D.

In 100 g of solution there are 20 g glycol (20/62 = 0.322 mol) and 80 g water (80/18 = 4.444 mol). Mole fraction of glycol = 0.322/(0.322 + 4.444) = 0.068.

  • A.

    0.25 is the mass ratio of glycol to water (20/80), not a mole fraction.

  • B.

    0.20 is the mass fraction, not the mole fraction.

  • C.

    0.932 is the mole fraction of water.

NCERT: Class 12 Chemistry, Chapter 1, 1.2

Practise Concentration of solutions

Practice at the level you choose, with the answer after every question; timed tests with the answers when you submit. Every question is verified against NCERT first.

Sign in to practise

More in Solutions