Noble gases A, B, C, D, E are passed through Dewar's flask at-`100^@C` A, C & E gases are adsorbed. Unadsorbed gases B, D are passed through another Dewar's flask at-`180^@C`. Gas B is adsorbed. The Dewar's flask al-`100^@C` is put in contact with another Dewars flask al-`193^@C`. The gas Eis diffused in it. Finally A & C are seperated by warming the flask from-`100^@C` w -`90^@C`. Ilere 'C' comes out
He and Ne gases respectively are

Options

A. A,B
B. B, D
C. C, D
D. D, B

Answer

A

Explanation

`He, Ne underset("Deewars flask "-180^@C)overset("another")to`Ne is absorbed. He is unadsorbed, He has weak vander wall forces.
Charcoal - 1 contains Ar, Kr, Xe is cooled to `-180^@C`. At this temp. Ar. Gets liquified while Kr & Xe remain adsorbed.

(1) B, D `to ` He, Ne