For the following reaction at equilibrium, which change would shift the position of equilibrium toward forming more products? (Circle your answer(s) as there may be more than one.)
2NOBr(g) 2NO(g) + Br2(g), ∆Hºrxn = +30 kJ/mol
A) Decrease the total pressure by increasing the volume. B) Add NO. C) Remove Br2. D) Raise the temperature. E) Add NOBr
It makes it difficult with no arrow. I have rewritten the equation and moved the dH so you can see it is an endothermic reaction.
2NOBr(g)+ heat =>2NO(g) + Br2(g)
Remember Le Chatelier's Principle says that when a system at equilibrium is disturbed, it will shift so as to undo what we've done to it.
a. Increased P shifts to the side with fewer mols. So decreasing P will shift to the side with more moles and that is the products.
b. Adding NO and the reaction tries to get rid of the NO added. Shifts to the left.
c. Removing Br2 means the rxn will try to add more Br2. Shift to the right.
d. Raise T and rxn tries to use up the added T. Shifts to the right.
e. Add ing NOBr and rxn tries to use it up. Shifts to the right.
To determine which change would shift the position of equilibrium toward forming more products, we need to consider Le Chatelier's principle. According to Le Chatelier's principle, a change in temperature, pressure, or concentration of reactants and products will cause the system to shift in a direction that counteracts the change.
In the given reaction, the forward reaction is the formation of products. Therefore, to shift the equilibrium toward forming more products, we need to decrease the concentration of reactants or increase the concentration of products.
Let's analyze each option:
A) Decrease the total pressure by increasing the volume:
According to Le Chatelier's principle, decreasing the pressure will favor the side with more moles of gas. In this reaction, the number of moles of gas is the same on both sides (2 moles on each side). Therefore, changing the volume will not shift the equilibrium.
B) Add NO:
Adding NO will increase the concentration of a reactant. According to Le Chatelier's principle, increasing the concentration of a reactant will shift the equilibrium toward the products. Thus, adding NO will shift the equilibrium toward forming more products.
C) Remove Br2:
Removing Br2 will decrease the concentration of a product. According to Le Chatelier's principle, decreasing the concentration of a product will shift the equilibrium toward the products. Thus, removing Br2 will shift the equilibrium toward forming more products.
D) Raise the temperature:
Since the reaction is exothermic (∆Hºrxn = +30 kJ/mol), increasing the temperature will shift the equilibrium in the endothermic direction to absorb the excess heat. In this case, the endothermic direction is the reactant side. Therefore, raising the temperature will shift the equilibrium toward the reactants.
E) Add NOBr:
Adding NOBr will increase the concentration of a product. According to Le Chatelier's principle, increasing the concentration of a product will shift the equilibrium toward the reactants. Thus, adding NOBr will not shift the equilibrium toward forming more products.
Based on the analysis above, the changes that would shift the position of equilibrium toward forming more products are:
- Adding NO
- Removing Br2
So, the correct answer is B) and C).
To determine which change would shift the position of equilibrium toward forming more products, we need to consider Le Chatelier's principle.
Le Chatelier's principle states that if a system at equilibrium is subjected to a change in temperature, pressure, or concentration of reactants or products, the equilibrium will shift to counteract the effect of that change.
In this reaction, the forward reaction is the formation of products (2NO + Br2), so we want to shift the equilibrium toward the right side of the equation.
Let's analyze each option:
A) Decrease the total pressure by increasing the volume: According to Le Chatelier's principle, decreasing the pressure will shift the equilibrium toward the side with more moles of gas. In this case, there are 3 moles of gas on the left side and 1 mole of gas on the right side. Therefore, decreasing the pressure (increasing the volume) would shift the equilibrium toward the right side, forming more products.
B) Add NO: Adding more NO will increase the concentration of reactants. According to Le Chatelier's principle, increasing the concentration of reactants will shift the equilibrium to the right, forming more products. Therefore, adding NO will shift the equilibrium toward the right side.
C) Remove Br2: Removing Br2, which is a product, will disrupt the equilibrium and cause a shift in the direction that produces more products. Therefore, removing Br2 will shift the equilibrium toward the right side.
D) Raise the temperature: Increasing the temperature favors the endothermic reaction, which is the forward reaction in this case. According to Le Chatelier's principle, increasing the temperature will shift the equilibrium toward the endothermic reaction. As a result, more products will be formed. Therefore, raising the temperature will shift the equilibrium toward the right side.
E) Add NOBr: Adding NOBr, which is a product in the forward reaction, will increase the concentration of products. According to Le Chatelier's principle, increasing the concentration of products will shift the equilibrium to the left, counteracting the added NOBr. Therefore, adding NOBr will not shift the equilibrium toward forming more products.
In conclusion, the changes that would shift the position of equilibrium toward forming more products are: A) Decrease the total pressure by increasing the volume, B) Add NO, C) Remove Br2, and D) Raise the temperature.