Could someone explain the reasoning for this?

6) Which of the following is a false statement about ALL reactions in equilibrium?
a) Increasing temperature shifts the reaction toward the products in an endothermic
reaction
b) Temperature effects on the equilibrium do not depend on ΔS
c) Increasing the amount of a solid salt (already present) will increase the ion
concentrations
d) All of the above
e) None of the above

I know the answer is C--but am not sure why. I know A is the opposite of what is stated, and B I am a little wishy washy on understanding it.

1 answer

Since you no c is correct, we can do away with d and e.
A is a true statement, contrary to what you say in your post about it being opposite.
A + B + heat ==> C + D.
Adding heat makes the reaction shift in order to use up the heat added; it can do that by shifting to the right using up heat in the process and making more of the products.

B. It may depend on delta S for some but not ALL equilibrium reactions.

C. A solid salt, already present, means you have a saturated solution. Therefore, the concn of the ions is as large as they will get. Although the solution process is dynamic, meaning that some ions are coming out of solution to form the solid while the solid is dissolving to form more ions in solution, the net total of the + ions remains the same and the net total of the - ions remains the same. Since it is already a saturated solution, the ion concentrations can't become larger.