Warm up (Dec 15) TODAY (last class before exam!): Discuss lab 15: due today! Please have it out for me to see now (ALL DONE WITH GRAPHS, PEOPLE!) One more tough ICE table question! Real life Equilibrium example: Haber process Quiz corrections Integrated problems and practice MC for review Keys on Moodle this weekend, of course! HW: STUDY YOUR BUM OFF!

Lab 15 Results What did you get for K? Give all results to 2 SF here: Sources of error?

Shifting with Pressure (demo) HCO3- (aq)   CO2 (g) + OH- (aq) COLORLESS PINK 4 HCl(g) + O2(g)  2 Cl2(g) + 2 H2O(g) With this reaction, what would an increase of pressure do to the equilibrium? Make a fresh 100 mL with 15 g NaHCO3 right before demo. Add HCl until just not pink again. Use a BIG beaker (600 mL) so it doesn’t splash everywhere, release pressure SLOWLY at end.

Apply It… Suggest four ways in which the concentration of hydrazine, N2H4, could be increased in an equilibrium described by the equation:   N2(g) + 2 H2(g)  N2H4(g)  ΔH = 95 kJ Pump out N2H4 as it is made to shift always to the right, increase temp, increase [N2] and/or [H2], increase pressure

And another one… Consider the reaction: I2 (g) + 3Cl2 (g)  2ICl3 (g) (ΔH = -) Give the equilibrium constant expression (Kc) State at LEAST 5 ways to shift the reaction to the reactants. Remove: iodine, chlorine. Add: ICl3 or heat. Decrease pressure.

Try another! The synthesis of HBr from hydrogen and liquid bromine has a Kp = 4.5 x 1015 at 25 C. The vapor pressure of liquid bromine at 25 C is 0.28 atm. Find the Kp of the following reaction:

One final tough ICE Table Consider the following chemical equation at a certain temperature: N2(g) + 3 H2(g)    2 NH3(g)         K = 1.56 x 10-4 M-2 Starting concentrations: [NH3] = 1.20 M; [N2] = 1.00 M; [H2] = 1.00 M   Calculate the equilibrium concentration of all species It is shifting toward the REACTANTS (if you calculate Q you will see). So, the ICE table is +x for the reactants and –x for the products!

The conundrum of real-life chemistry Consider the Haber Process to form ammonia gas: 3 H2 (g) + N2 (g)  2 NH3 (g) ΔH= -92 KJ mol-1 To produce the highest yield, what would YOU do? High Pressure Low Temperature BUT: Low temp slows the reaction and high pressure is expensive 

The conundrum of real-life chemistry Nobel Prize in 1919 for this!

The conundrum of real-life chemistry

STUDY Quiz Corrections Due NOW  Then I’ll give you your review packet to work on I just have one comment: STUDY

AP Integrated Problems WS 5 - Review A great way to review for the semester exam! Last three pages are practice MC – I recommend doing those this weekend in QUIET, EXAM-STYLE setting (by yourself, with equations sheets, no calc) We will do a mock MC during our study session Monday at 12:30-1:30 right after the 2R exam (before lunch) – BE ON TIME

Homework Day 5 Semester 1 MC Final on Tuesday Next week Study Hard! I will give you your Winter Break Review Packet at the exam and extra topics to work on over break. This is VITAL to getting the score you dream of! Make sure you come to YOUR review period for a mock MC practice and any last minute qs!