. For the gas reaction at low pressure

2NOBr ¡ê 2NO + Br2 ¥ÄH = +61.1 kJ

which of the following statements are true?

a) Adding more Br2 shifts reaction to the right

b) Removing some NOBr shifts reaction to the left

c) Increasing temperature shifts reaction to the right

d) Changing temperature is the only thing that does not affect Kp

e) The use of a catalyst will not cause any change in the concentrations once equilibrium is reached

oops the reaction should be

2NOBr <-> 2NO + Br2 (delta)H = +61.1 kJ

It's tough to read the equation. I can't make out the symbols. Where is the arrow? What are your thoughts on the question?

Adding Br2 will shift the reaction to the left.

Removing NOBr will shift the reaction to the left.
You try the others.

I just fixed the equation above but here it is again 2NOBr <-> 2NO + Br2 (delta)H = +61.1 kJ

I thought b and e are true however the computer keeps saying that answer is wrong.

b and e ARE true. You can take that to the bank. The computer is (a) wrong or (b) or you keying into the wrong question. a,c,d or not true.

no I've entered b and e several times before into the computer (and now again) for the correct question so now I am going to email my instructor, thank you

If your instructor thinks b and e are NOT true I would like to know it AND I would like to know the reason why. LeChatelier may turn over in his grave.

Haha yes he probably will. I will let you know.

My profesor says that b and e are true but c is also true. The reaction will shift toward the right with a temperature increase because it is endothermic. I did type in bce before but because the computer said it was incorrect I changed my answer. :( It is too late to fix it now, however thank you for your help.

To answer these questions, we need to understand how changes in pressure, concentration, temperature, and the presence of a catalyst affect the equilibrium of a gas reaction. Let's go through each statement and explain whether it is true or false:

a) Adding more Br2 shifts reaction to the right:
In this reaction, increasing the concentration of Br2 will indeed shift the reaction to the right. This is because there are more reactant molecules available, and according to Le Chatelier's principle, the reaction will favor the forward direction to consume the excess Br2.

b) Removing some NOBr shifts reaction to the left:
Removing some NOBr will shift the reaction to the right, not the left. This is because when a reactant is removed, the equilibrium will shift to produce more of that reactant to restore the balance.

c) Increasing temperature shifts reaction to the right:
Increasing the temperature of an exothermic reaction like this one will shift the reaction to the left. This is because increasing the temperature favors the reverse direction of the reaction to absorb the excess heat. In this case, it means fewer products (NO and Br2) will be formed.

d) Changing temperature is the only thing that does not affect Kp:
This statement is false. Changing temperature indeed affects the equilibrium constant (Kp) of a reaction. Temperature changes alter the ratio of products to reactants at equilibrium, which subsequently changes the value of Kp.

e) The use of a catalyst will not cause any change in the concentrations once equilibrium is reached:
This statement is true. A catalyst accelerates the forward and reverse reaction rates equally, but it does not affect the position of the equilibrium or the concentrations of the reactants and products at equilibrium. Therefore, once equilibrium is reached, the use of a catalyst will not cause any change in the concentrations.