One litre of a gas weighs `2g` at `300 K` and 1 tm pressure. If the pressure is changed to `0.75` atm at which of the following temperatures, will one litre of the same gas weight `1 g`?

Options

A. `450 K`
B. `600 K`
C. `800 K`
D. `900 K`

Answer

a

Explanation

According to ideal gas equation,
`PV = nRT = w//M RT`
For a particular gas :
`(P_(1)V_(1))/(P_(2)V_(2)) = (n_(1)RT_(1))/(n_(2)RT) = (w_(1)RT_(1))/(w_(2)RT_(2))`
`(1 xx 1)/(0.75 xx 1) = (2 xx R xx 300)/(1 xx R xx T_(2))`
or `T_(2) = 2 xx 300 xx 0.75 = 450 K`