Various constituents of liquid possess different boiling points, So they can be separated by fractional distillation. It can be done by using claude's apparatus. When condensed air passed through Claude's apparatus, both oxygen and Nitrogen ger condensed separately. He and Ne are collected with liquid nitrogen. Ar, Kr, Xe are collected with liquid oxygen. After removal of `N_2` by heating with `CaC_2` He & Ne are cooled to 20 K with liquid `H_2` After removal of `O_2` with Cu, Ar, Kr, Xe are cooled with liquid nitrogen and Ar separated out. Finally liquid kr and Xe can be separated by fractional distillation :
In this process the chemical that is not involved

Options

A. He, Xe
B. He, Ne
C. `Ar, O_2`
D. `N_2, O_2`

Answer

C

Explanation

`CaC_2 + N_2 overset(800- 1000^@C)to CaCN_2 + C_("graphite")`
`2Cu + O_2 to 2CuO`
`{:(Ar to 87.28),(O_2 to 90.0):}}`Nearly same values