Equal weights of two gases of molecular mass 4 and 40 are mixed. The pressure of the mixture is 1.1 atm. The partial pressure of the lighter gas in this mixture is

Options

A. 0.55 atm
B. 0.11 atm
C. 1.0 atm
D. 0.1 atm

Answer

C

Explanation

Moles of lighter gas `= ( W )/( 4)`
Moles of heavier gas `= ( W)/( 40)`
Mole fraction of lighter gas
`= ( W //4)/( W //4+ W// 40) = 10 //11`
Partial pressure of lighter gas
= Mole fraction `xx` Total pressure
`= ( 10)/( 11) xx 1.1 = 1.0 atm`