The equilibrium `N_(2) (g) + O_(2) (g)hArr 2NO (g)` is established in a reaction vessel of `2.5` L capacity. The amounts of `N_(2)` and `O_(2)` taken at the start were respectively 2 moles and 4 moles. Half a mole of nitrogen has been used up at equilibrium. The molar concentration of nitric oxide is:

Options

A. (A) `0.2`
B. (B) `0.4`
C. (C) `0.6`
D. (D) `0.1`

Answer

B

Explanation

`N_(3) + O_(2) hArr 2NO`
Initial `2` molas `4` molas
At Eq. `2-(1)//(2) 4-(1)/(2) 2xx(1)/(2)=1` mol
Molar concentration of `NO` at equilibrium`xx(1)/(2.5)=0.4`