Easy MCQ +4 / -1 PYQ · JEE Mains 2020

The average molar mass of chlorine is 35.5 g mol–1. The ratio of 35Cl to 37Cl in naturally occuring chlorine is close to :

  1. A 1 : 1
  2. B 2 : 1
  3. C 3 : 1 Correct answer
  4. D 4 : 1

Solution

Average molar mass = ${{{n_1}{M_1} + {n_2}{M_2}} \over {\left( {{n_1} + {n_2}} \right)}}$ <br><br>$\therefore$ 35.5 = ${{35x + 37y} \over {x + y}}$ <br><br>$\Rightarrow$ 1.5y = –0.5x <br><br>$\Rightarrow$ ${x \over y} = {3 \over 1}$

About this question

Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept

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