10 ml of ethane gas is mixed with 40ml oxygen gas in an eudiometer tube at `30^@C` and fired such that complete reaction occurs. When the resulting gases are cooled to `30^@C`, the volume of eudiometer becomes 26ml. What is the vapour pressure of water at `30^@C`? Neglect the volume occupied by liquid water. Pressure is 1 atm and constant throughout.

Options

A. 1 atm
B. 29.23 mm Hg
C. 26 mm Hg
D. 32.55 mm Hg

Answer

B

Explanation

`{:(,C_(2)H_(6),+,7/2 O_(2),to,2CO_(2)(g),+,3H_(2)O(l)),(t=0,10 ml,,35 ml,,0,,0),(t=t,x,,"5 ml left",,20 ml,,):}`
Volume of water vapoures =1 ml
Pressure =`1/26xx760=29.23 mm Hg`