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Chemistry 104B. Dr. Christine Yerkes 207 Chem Annex 333-6353 cyerkes@illinois.edu Mon. and Wed. 11:00 - 12:00 Tues. and Thurs.1:00 - 2:00 or by appointment. Required Text:. Chemistry, 8th ed., Zumdahl. Recommended I >clicker. Quiz sections began: Tuesday, Jan. 17. Grading Policy:.
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Chemistry104B Dr. Christine Yerkes 207 Chem Annex 333-6353 cyerkes@illinois.edu Mon. and Wed. 11:00 - 12:00 Tues. and Thurs.1:00 - 2:00 or by appointment
Required Text: Chemistry, 8th ed., Zumdahl Recommended I >clicker Quiz sections began: Tuesday, Jan. 17
Grading Policy: On-line Homework: 76 pts. Quiz score: 150 pts. Discussion Quizzes 24 pts. Hour Exams (3 x 150) 450 pts. Final Exam 300 pts. 1000 pts. No make-up quizzes or exams
Grades 1000 points total 97-100% (970 - 1000) = A+ 93 - 96% (930 - 969) = A 90 - 92% (900 - 929) = A- 87 - 89% (870 - 899) = B+ 83 - 86% (830 - 869) = B 80 - 82% (800 - 829) = B- etc., etc., etc.
Quiz scores: weekly quizzes - material from Lecture and Quiz section Quizzes on LON-CAPA open Wednesday at 5:00 open for 1 week Three tries – 1st worth 15 2nd worth 13.5 3rd worth 12 keep 10 highest 150 points
On-line Homework: 13(?) Homework assignments on LON-CAPA due dates in the on-line Syllabus and calendar credit for all problems completed by deadline normalized to 76 points
Quiz scores: weekly quizzes - material from Lecture and Quiz section each quiz worth 15 points - keep 10 highest On-line LON-CAPA attempt 1 100% attempt 2 90% attempt 3 80% 150 points
Discussion Sections Worksheets in groups Discussion Quiz old hour exam problem 5 minutes 3 pts for correct 2 pts for partial 1 pt for attendance Keep 12 highest 24 pts max 12 bonus points
Course Homepage http:// www. chem.uiuc.edu Course Web Sites Chem 104A Lon-Capa = net i.d. Password = AD password homepage
wmax Go= 2 CuCl2 (aq) AlCl3 (aq) 2 + Al (s) 3 + Cu (s) 3 2 Al3+ + 6 Cl- + 3 Cu 3 Cu2+ + 6 Cl- + 2 Al -481 kJ 0 kJ 65.0 kJ 0 kJ Go = (3 x 0) + (2 x -481) - (2 x 0) - (3 x 65) Go = -1157 kJ - n V F w = - Pext w = Electrochemical work
3 CuCl2 (aq) 2 AlCl3 (aq) + 3 Cu (s) + 2 Al (s) AlCl3 aluminum chloride Al (s) = Al0 Al0has _____ electrons 10 13 Al3+has ______ electrons 3+ oxidation state = 0 oxidation state = Al0 loses___ e- 3 increase oxidation number losing e- = oxidation 3+ 0 LEO GER Lose Electrons Oxidation Gain Electrons Reduction Cu2+ Cu (s) 2+ 0
Rules for oxidation numbers 1. Oxidation number for elements is zero. N2, Na(s), O2, Co(s), He (g) • Oxidation number of monatomic ions • is the same as their charge Group IA = +1 Al3+, Zn2+, Cd2+, Ag+ Group IIA = +2 • Oxidation number of oxygen in most compounds • is –2. Exceptions: H2O2, O22- (peroxides) –1 4. Oxidation number of hydrogen is +1 Exceptions: bonded to metals LiH -1 5. Fluorine is always –1. Other halogens are –1. Exceptions: bonded to O or F, they are positive
Assign oxidation numbers to all of the elements: Li2O Li = O = PF3 P = F = HNO3 H = O = N = MnO4- Mn = O = Cr2O72- Cr = O =
What is the oxidation state of the highlighted element? P2O5 NaH SnBr4 BaO2
Redox reactions H2 (g) + 2H+ (aq) + Zn Zn (s) 2+ Zn oxidation state H oxidation state
+ O2 (g) 2H2O(l) 2H2(g) H loses or gains electrons is oxidized or reduced oxidizing or reducing agent O loses or gains electrons is oxidized or reduced oxidizing or reducing agent
What is the oxidation state of S in each of these compounds: H2S H = S = S8 S = SCl2 S = Cl = Na2SO3 S = O = Na = SO42- S = O = Which of these compounds can not act as a reducing agent? Which of these compounds can not act as a oxidizing agent?
+ Al(s) + MnO4- Al(OH)4- + MnO2 2H2O H2O What is being oxidized? Al What is oxidation? MnO4- Al(OH)4- LEO MnO2 How many e-? What is being reduced? GER What is the reducing agent?
Cd(OH)2 + Ni(OH)2 + NiO2 + 2H2O Cd(s) What is being oxidized? What is being reduced? What is the oxidizing agent? What is the reducing agent? How many electrons are transferred?