The equilibrium
`N _(2) (g) + O _(2) (g) hArr 2 NO (g) ` has
been established in a reaction vessel of 2.5 L. The amount of `N_(2)` and `O_(2)` taken initially were 2 moles and 4 moles respectively. 0.5 mol of nitrogen has been used up at equilibrium. What is the molar concentration of nitric oxide ? (give your answer by multiplying it with 100)

Answer

40

Explanation

Initially,
`{:(N _(2) " " " " O _(2) " "hArr" " 2 NO ) ,( 2"moles" " ""4moles"):}`
At Equilibrium,
`2 - (1)/(2) (4) - (1)/(2) (2) xx (1)/(2) = 1 ` mol
Molar conc. Of NO at equilibrium
`= (1)/(2.5) = 0.4`
Hence, the answer which is to be expressed by multiplying it with 100, is 40.