Question

A gas jar of 10 litre volume filled with `O_(2)` at 300 K is connected to glycerine manometer. The maonometer shows 5 m difference in the level as shown in figure. What will be the number of moles of `O_(2)` in the gas jar ?
(Given `d_("glycerine") = 2/72 g // mL , d_("mercury") = 13.6 g//mL`)
A. `0.64 mol`
B. `0.4 mol`
C. `0.94 mol`
D. `0.36 mol`

Answer 1

Correct Answer - C
`(h xx d xx g)_(Hg) = (h xx d xx g)_("glycerine")`
`(h xx 13.6)_(Hg) = (5 xx 2.72)_("glycerine")`
`h_(Hg) = 1m`
`P_("gas") = (1 + 0.76) m`
`= 1760 mm Hg`
`PV = nRT`
`(1760)/(760) xx 10 n xx 0.0821 xx 300`
`n = 0.94 mol`