Question

a mixture of 2 gases contains gas A with mol mass 40 and B with 80 and have vapour density 25.the mole% of B is

Answer 1

The % of B is 25%.

It is now known that the relation between the vapour density and the molecular mass of a compound or mixture is given as follows:

M = 2 x VD

So, molecular mass of the mixture is 50 units.

Now, assuming that the % of B is x %, we can take % of A to be (100-x) %.

Substituting the equation of the mass relation with the assumed mass percentages, we find that the percentage of B comes out to be 25%.

Answer 2

B% is 25%

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