Nitric oxide reacts with Br2 and gives nitrosyl bromide as per reaction given below:

2NO (g) + Br2 (g) 2NOBr (g)


When 0.087 mol of NO and 0.0437 mol of Br2 are mixed in a closed container at constant temperature, 0.0518 mol of NOBr is obtained at equilibrium. Calculate equilibrium amount of NO and Br2.

The chemical reaction is,

Initial amount:


Let x amount of Br2 be reacted to attain equilibrium. Then amount of substance left at equilibrium,


2NO (g) + Br2 (g) 2NOBr (g)


Equilibrium amount: 0.087 – 2x 0.0437 – x 2x


Given, equilibrium concentration of NOBr is 0.0518,


i.e, 2x = 0.0518


x = 0.0259


Thus,


Amount of NO at equilibrium = 0.087 - 2 × 0.0259


= 0.0352 mole


Amount of Br2 at equilibrium = 0.0437 – 0.0259


= 0.0178 mole


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