Agaseous mixture composed of 20% ch4, 30% c2h4, 35% c2h2, and 15% c2h20. what is the average molecular weight of the mixture? a) 20 b) 9.25 c) 25 d) 6.75

The correct answer is Option d.

Explanation:

We are given:

Mass percentage of = 20 %

So, mole fraction of = 0.2

Mass percentage of = 30 %

So, mole fraction of = 0.3

Mass percentage of = 35 %

So, mole fraction of = 0.35

Mass percentage of = 15 %

So, mole fraction of = 0.15

We know that:

Molar mass of = 16 g/mol

Molar mass of = 28 g/mol

Molar mass of = 26 g/mol

Molar mass of = 48 g/mol

To calculate the average molecular mass of the mixture, we use the equation:

where,

= mole fractions of i-th species

= molar masses of i-th species

= number of observations

Putting values in above equation:

Hence, the correct answer is Option d.