2. Given the Reaction H2O(L) + CO3(2-)(Aq) Àß OH(-)(Aq) +HCO(3-)(Aq) Please Write out Its

SI Chem 178

Thursday Jan 24th

Focus on Ch 15

Leader: Emily

Review:

1. Quiz Question Remix: You are given a 0.876M solution of sucrose with a density of 1.4 kg/L. (Molar mass of sucrose is 342.3g) Your prof tells you he needs to know the molality.

2. Given the reaction H2O(l) + CO3(2-)(aq) àß OH(-)(aq) +HCO(3-)(aq) please write out its Kc equation. Is this heterogeneous?

3. I have now manipulated the previous equilibrium: 4H2O(l) + 4CO3(-2)(aq) àß 4OH(-)(aq) + 4HCO(3-)(aq) What has happened to its Kc now? What if I flipped the reaction and asked you to write the Kc with respect to OH- and HCO-3 as reactants?

Practice: Sugg probs for Fri: 4, 7, 8, 10, 16bfg, 23, 28, 37, 39, 46, 51, 55, 62

ICE Advice:

Problem 15.38: H2(g) + Br2(g) àß 2HBr (g) At equilibrium, vessel has 0.566g H2. Find Kc.

H2: 1.374g

Br2: 70.31g

T=700 Deg K

V= 2L

15.51 Find the equilibrium concentrations of NO, N2, and O2 given the Kc for this reaction is 2.4x10^3 and that NO starts at a concentration of 0.175M. (**See page 629 15.12 to be walked through an example like this!)

Looking Ahead: Le Chatelier’s Principle and Catalysts

What things can have an effect on an equilibrium system?

What happens if you add heat to an endothermic reaction?

What happens if you add heat to an exothermic reaction?

What happens when you remove product from a product-favored equilibrium? How can this be advantageous?

What happens when you add pressure to a gaseous system? Which side will be favored? What about increasing volume?

What does a catalyst do? In an equilibrium reaction/equation, what do you predict this will affect? Can you visually depict what a catalyst does?