Chemical Equilibrium

When two ____________ processes equal

eachother in ________

Compare rxtion favored

If ___ > ___ ________ If ___ < ___ ________ If ___ = ___ ________

Equilibrium Nonequilibrium

Consequences at Equilibrium

[ ]’s are

Rates of forward and reverse are

[ ]’s are dictated by

same/constant

same/constant

__________

establishing it

quantifying it

manipulating it

__________________________________________

Ch. 13 A.P. Chem opposing rate

Reactions are _________reversible

maybe!!

stoich. and intitial [ ]

Mass Action Expression [P]x/[R]y

Kc

KpKc (RT)n = Kp

Ksp

Q

Q K reverseQ K forwardQ K at eq.

Le Chatelier’s Principle

An equilibrium system that is stressed will respond to a stress in such a way to counteract the stress

Conc. Changes

Pressure (Volume ) Changes

Temp. Changes

Find Molar Solubility

Spectrophotometry/ Beer’s Law

Typical problem for chapter 13.

Reagents were put together at 298 K such that initially, in 95.0 mL of solution, there were in moles, the following amounts of both products and reactants in a beaker for the subsequent reaction to occur:

0.023 mol 0.040 mol 0.052 mol

A2+(aq) + B-

(aq) ↔ AB+(aq)

(colorless) (colorless) (blue)

H is negative for this process and Kc = 90. Find the concentrations for all species at equilibrium and then once at equilibrium suggest four ways to get the solution to turn darker.

Initial: 0.24M 0.42M 0.55M Q= 0.55/(0.24)(0.42)

Q= 5.5Change: -x -x +x

Eq: 0.24-x 0.42-x 0.55+x

K= 90 = (0.55+x)/(0.24-x)(0.42-x)

Q<K forward reaction favored

x = 0.20

(0.04 M) (0.22 M) (0.75M)

[A2+]↑ , [B-]↑ ,Temp.↓ ,[AB+]↑

0 = 90x2 - 60x + 8.5

Write the reaction equation for the dissociation of copper (II) hydroxide in water and find the K value for the reaction.

Cu(OH)2(s) <-> Cu2+(aq) + 2OH-

(aq) Ksp= 1.6 x 10-19

What if a strong acid was added to the saturated solution?OH- removed, forward rxtion favored, solid dissolved

Shifts to produce more product

Name 3 other ways (based on things learned this year) to get the copper (II) hydroxide to further dissolve.

Add water, heat, or ammonia.

What would the sol’n (above the undissolved solid) look like?Clear and colorless (conc. of Cu2+ would be too low…no blue).

Which of these would make the sol’n bluer?