Consider the adjacent diagram. Initially, flask `A` contained oxygen gas at `27^(@)C` and `950 mm` of `Hg`, and flask `B` contained neon gas at `27^(@)C` and `900 mm`. Finally, two flask were joined by means of a narrow tube of negligible volume equipped with a stopcock and gases were allowed to mixup freely. The final pressure in the combined system was found to be `910 mm` of `Hg`.

If flask `B` were heated to `127^(@)C`, maintaining flask `A` at constant temperature of `27^(@)C`, final pressure (in `mm Hg`) in the combined system would have been

Options

A. `1007`
B. `1250`
C. `1137.5`
D. `1990`

Explanation

`n_(total)=Const`.

`implies (950xxV_(A))/(Rxx300)+(900xxV_(B))/(Rxx300)=(PxxV_(A))/(Rxx300)+(PxxV_(B))/(Rxx400)`
`implies 950V_(A)+900xx4V_(A)=PxxV_(A)+(3)/(4)xxPxx(4V_(A))`
`implies P=(950+900xx4)/(1+3)=1137.5 mm Hg`