Reaction Rates and Equilibrium

Question 1

Accurate statements regarding the equilibrium constant of a reaction include all of the following except:

a. Keq will be affected by a change in temperature
b. Keq will be unaffected by a change in product concentration
c. Keq will be unaffected by a change in reaction concentration.
d. Keq will be affected by change in pressure

Answer 1

D. is correct b/c Keq is not affected by change in pressure** although it does vary with temperature, even though it is only a little bit. Changes in reacatant concentration and product concentration affect Q not Keq so this answer is not correct.

Question 2

Q 13 Qbank 11-25

The molar solubility of silver chloride is 1.34 × 10-5. What is the Ksp of this compound?

A.

1.8 × 10^-25

B.

1.8 × 10^-10

C.

3.6 × 10^-10

D.

1.34 × 10^-5

Answer 2

Since silver chloride has a formula of AgCl, its Ksp expression is simply [Ag+][Cl-]. To translate between molar solubility and Ksp, let’s give molar solubility a variable, “x.” In other words, “x” moles of AgCl dissolve in a single liter of water. Since a 1:1 molar ratio exists between dissolved AgCl and the amount of aqueous Ag+ present, we can say that our [Ag+] value is also “x.” Luckily for us, the same is also true for [Cl-]. When we plug in these variables, we see that Ksp = (x)(x), or Ksp = x2. (1.34 × 10-5)2 is equal to approximately 1.8 × 10-10.