As always… OWL Lon-Capa assignments Lecture videos Textbook HW: equilibrium (due Monday) Quiz: Mon-Wed next week Lecture videos Textbook Read Do text homework

Exam I Thursday, September 27, 7:00-9:00 pm; rooms are on the website. Conflict: (9/27) 4:30-6:30pm in 219 Greg; sign up in 1026 CA (starting 9/20) Conflict with conflict? Email me right away. Review sessions: Monday (9/24): 160 English Building (6-8 pm) Tuesday (9/25): 259 English Building (6-8 pm)

Clicker Question Which of the following is true about chemical or physical equilibrium? a) It is microscopically and macroscopically static. b) It is microscopically and macroscopically dynamic. c) It is microscopically static and macroscopically dynamic. d) It is microscopically dynamic and macroscopically static. e) I do not know.

CO(g) + H2O(g) CO2(g) + H2(g) Clicker Question Consider the following equation: CO(g) + H2O(g) CO2(g) + H2(g) Which of the following must be true at equilibrium? a) [CO2] = [H2] because they are in a 1:1 mole ratio in the balanced equation. b) The total concentration of reactants is equal to the total concentration of the products. c) The total concentration of the reactants is greater than the total concentration of the products. d) The total concentration of the products is greater than the total concentration of the reactants. e) None of these is true.

Change in Concentration/Time

Reaction Rate Over Time

Physical Equilibrium

Change Related to Coefficients

Fe3+(aq) + SCN-(aq) FeSCN2+(aq) Clicker Question You mix 500.0 mL of 4.00 M Fe(NO3)3 with 500.0 mL 6.00 M KSCN. They react according to the following equation:  Fe3+(aq) + SCN-(aq) FeSCN2+(aq)   FeSCN2+ in solution appears red (and the reactants are colorless) so you use a spectrophotometer and determine the concentration of FeSCN2+ at equilibrium to be 1.00 M. Determine the value of the equilibrium constant, K. a) 0.0417 b) 0.0667 c) 0.100 d) 0.167 e) 0.500