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Most Important Selected Qs for JEE AdvancedChemistrySome Basic Concepts of Chemistry

A mixture of O ₂ and gas " Y " (mol. wt. 80) in the mole ratio a : b has a mean molecular weight 40 . What would be mean molecular weight, if the gases are mixed in the ratio b : a under identical conditions? (gases are non-reacting) :

Correct answer

72

Step-by-step solution

Let mole fraction of O ₂ is x 40=32 x+80(1-x) or x=5 / 6a+b=x:(1-x)= 5 6 : 1 6 When ratio is changed M_ mixture =32 1 6 +80 5 6 =72

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