A manometer attached to a flask contains ammonia gas have no difference in mercury level initially as shown in diagram. After sparking into the flask, ammonia is partially dissociatedas `2NH_(3)(g) to N_(2)(g)+3H_(2)(g)` now it have difference of 6 cm in mercury level in two columns, what is partial pressure of `H_(2)(g)` at equilibrium?

Options

A. `9 cm Hg`
B. `18 cm Hg`
C. `27 cm Hg`
D. `15 cm Hg`

Answer

A

Explanation

`2NH_(3)(g) to N_(2)(g)+3H_(2)(g)`
`{:(" "76" "0 " "0 " ""Before sparking "),(76-2x" "x " "3x " "" After sparking at eqm "):}`
Partial pressure of `H_(2)= 3xx 3 = 9 cm Hg`.