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EEJ MAIN Chemistry QUESTION #7518
Question 1

In a gaseous mixture, the ratio of masses of oxygen to nitrogen is 1 : 4. What is the ratio of the number of molecules of O$_2$ to N$_2$?

  • 1:08
  • 3:16
  • 1:04
  • 7:32✔️
Correct Answer Explanation

Let mass of O$_2 = 1$ g and mass of N$_2 = 4$ g.

Moles of O$_2 = \dfrac{1}{32}$ ; Moles of N$_2 = \dfrac{4}{28} = \dfrac{1}{7}$

Ratio $= \dfrac{1/32}{1/7} = \dfrac{7}{32}$

So the ratio of molecules O$_2$ : N$_2 = \mathbf{7 : 32}$