Answer:
Adding of Br2 to the reaction mixture favours/increases the concentration of BrNO, causing the reaction progress to shift to the left/reactants (away from the forward reaction/products).
Adding of BrNO to the reaction mixture favours/increases the concentration of Br2 and NO (the products), causing the reaction progress to shift to the right/products (away from the backward reaction/reactants).
Explanation:
2BrNO(g) ⇌ 2NO(g) + Br2(g)
According to the Le Chatellier's principle, when one of the factors involved the equilibrium (concentration, pressure and temperarure) of a chemical reaction changes, the equilibrium position of the reaction shifts to remedy this change.
When the concentration of one of the reactants or products changes, the whole position of equilibrium of the reaction shifts to account for this change.
From the reaction given in the question, 2BrNO is on the reactant side and 2NO & Br2 are on the product side.
If more of Br2 is then added to the reaction, it causes an overload of Br2, a product of the reaction, in the reaction setup and the equilibrium responds by shifting to the left, favouring the backward reaction and leading to the production of more BrNO (reactants).
If more of BrNO is then added to the reaction, it causes an overload of BrNO (a reactant in the reaction) in the reaction setup and the equilibrium responds by shifting to the right, favouring the forward reaction and leading to the production of more Br2 and NO (products).
Hope this Helps!!!
