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Chem 108: Lab Week 12. Sign in / Pick up Papers. Pick up Global Warming Handout Questions plus Scantron (Due next week). Chem 108: Class/ Lab Week 12. 1) Fluid Exchange (Handout) Due Today 2) Acid-Base Equilibrium Experiment (Handout) Due Today 3) Any missing assignments Due Today.
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Chem 108: LabWeek 12 Sign in / Pick up Papers Pick up Global Warming Handout Questions plus Scantron (Due next week)
Chem 108: Class/ Lab Week 12 1) Fluid Exchange (Handout) Due Today 2) Acid-Base Equilibrium Experiment (Handout) Due Today 3) Any missing assignmentsDue Today Pick up Global Warming Handout Questions plus Scantron (Due next week)
Did you have a Happy Halloween, “All Hallows Eve”? Do you believe in Vampires & their thirst for blood.......?
TODAY:The day after All Hallows Eve Día de los Muertos / Day of the Dead
BloodLight & The Chemistry of Vision Color(s) of Blood & Vampires
B&W vs. Color vision : Rods vs. Cones Color Vision Experiment/Exercise
Absorbed color Observed color
ColorsofBlood • Result from absorption of visible radiation by hemoglobin: • A protein that contains Fe(II) bonded through d-orbitals to an organic molecule referred to as porphyrin • Occurs when radiation has the quantum energy needed to raise an e-from its ground state to an excited state • Oxygenated blood is bright red ~ 620 nm; Deoxygenated blood is dark bluish-red
https://www.youtube.com/watch?v=8OC5rji1stI&feature=push-u&attr_tag=uR2iOHN7_TVAYFW5-6https://www.youtube.com/watch?v=8OC5rji1stI&feature=push-u&attr_tag=uR2iOHN7_TVAYFW5-6 Iron (II) plus Porphyrin 2+ heme https://www.youtube.com/watch?v=WLI1ooXfEVs
Did you ever have a vampire encounter? Is Bram Stoker’s “Dracula” pure fiction? Do vampires have any preference arterial or venous blood? Vampires & Porphyria?Eduard Munch
Porphyria Erythropoietic porphyria symptoms: severe photosensitivity, swelling, pain, and burning; requires avoidance of bright sunlight; produces brown canine teeth that fluoresce in ultraviolet light; produces hemolytic anemia. Drinking large quantities of blood can alleviate the symptoms. Garlic activates an enzyme that destroys them faster and makes the symptoms of porphyria worse. http://en.wikipedia.org/wiki/Porphyria Q. "Why is a baby like a vampire? A "Because it sleeps all day and feeds all night."
Edvard Munch (1863–1944) SF MOMA July 1-October 5, 2017 Eduard Munch
Chem 108: Exam 2 Exam 2: Divide raw score by 117 (normalized to 100%) Raw point average = 76.6 +/- 23.6 Exam 1 Raw point average = 76.9 +/- 15.9 Complete Grades will be posted before Monday’s class with an October 30 link on the calendar
Chem 108: LabWeek 12 To Do & DUE Today Have signed before leaving lab.
Neutralizations / Titrations Chem 108 titration: phenolphthalein indicator Chem 120/121 Titration Curves
http://chemconnections.org/general/movies/pHEstimation.swf pH Estimation
Due Today http://chemconnections.org/general/chem108/Acids-Bases%20Guide.html
Neutralization Reactions Would there be a difference in the reaction of acetic acid versus HCl?
Aqueous Reactions: NeutralizationNet Ionic Equations HCl(aq) +NaOH (aq) NaCl (aq) + H2O(l) acid base salt water H+(aq) + OH -(aq) H2O(l)
Aqueous Reactions: NeutralizationNet Ionic Equations CH3COOH(aq) +NaOH (aq)CH3COONa (aq) + H2O(l) CH3COO-(aq) + H+(aq) +Na+(aq) + OH-(aq)CH3COO-(aq) + Na+(aq) + H2O(l) acid base salt water Same Net Ionic Equation (NIE) for any neutralization Eg. H2SO4 2 H+(aq) + 2 OH -(aq) 2 H2O(l) H+(aq) + OH -(aq) H2O(l) __________________________ 2
Acid-Base Titration Part 1: Standardization (in pairs)
Chem 108: LabWeek 12 To Do (with a partner) Have signed before leaving lab.
Aqueous Reactions: NeutralizationNet Ionic Equations HNO3(aq) +KOH (aq) KNO3(aq) + H2O(l) acid base salt water • 25.00 mL of MHCL = 0.2160 M nitric acid solution was titrated with a potassium hydroxide solution. It required 24.20 mL as an average of three trials to reach a faint pink color. • MKOH = ? H+(aq) + OH -(aq) H2O(l)
Aqueous Reactions: NeutralizationNet Ionic Equations HNO3(aq) +KOH (aq) KNO3(aq) + H2O(l) acid base salt water • 25.00 mL of MHCL = 0.2160 M nitric acid solution was titrated with a potassium hydroxide solution. It required 24.20 mL as an average of three trials to reach a faint pink color. ?MKOH= [MHNO3 x VHNO3 / VKOH ] [? molKOH / ? molHNO3] 0.2160molHNO3 x 0.02500 LHNO3 x 1 molKOH LHNO3x0.02420 LKOHx 1 molHNO3 = = 0.2231 MKOH
QUESTION A 35.00 mL sample of 0.2250 M HBr was titrated with 42.30 mL of KOH. What is the concentration of the KOH? 0.0930 M 0.3030 M 0.2720 M 0.1860 M 0.3720 M
Answer HBr(aq) +KOH (aq) KBr (aq) + H2O(l) acid base salt water A 35.00 mL sample of 0.2250 M HBr was titrated with 42.30 mL of KOH. What is the concentration of the KOH? ?MKOH= [MHBrx VHBr / VKOH ] [? molKOH / ? molHBr] 0.2250molHBr x 0.03500 LHBr x 1 molKOH LHNO3x0.04230LKOHx 1 molHBr = = 0.1860 MKOH Answer D.
QUESTION A 35.00 mL sample of 0.2250 M H2SO4 was titrated with 42.30 mL of KOH. What is the concentration of the KOH? 0.0930 M 0.3030 M 0.2720 M 0.1860 M 0.3720 M
Answer H2SO4(aq) +2 KOH (aq) K2SO4(aq) + 2 H2O(l) acid base salt water A 35.00 mL sample of 0.2250 M H2SO4 was titrated with 42.30 mL of KOH. What is the concentration of the KOH? ?MKOH= [MH2SO4x VH2SO4 / VKOH ] [? molKOH / ? molH2SO4] 0.2250molH2SO4 x 0.03500 LH2SO4x 2molKOH LH2SO4x0.04230LKOHx 1 molH2SO4 = = 0.3720 MKOH Answer E.
Chem 108: LabPart 2: Week 13 To Do next week (individually)
A 25.0 mL sample of 0.105 M HCl was titrated with of NaOH. What is the concentration of the NaOH? A) 0.0833 M B) 0.132 M C) 0.105 M D) 0.075 M E) none of the above Answer: A A 35.0 mL sample of 0.225 M HBr was titrated with 42.3 mL of KOH. What is the concentration of the KOH? A) 0.157 M B) 0.303 M C) 0.272 M D) 0.186 M E) none of the above Answer: D Exactly 17.0 mL of a H2SO4 solution was required to neutralize 45.0 mL of 0.235 M NaOH. What was the concentration of the H2SO4 solution? Given: H2SO4 (aq) + 2NaOH (aq) → 2H2O (l) + Na2SO4 (aq) A) 5.63 M B) 0.622 M C) 0.00529 M D) 0.311 M Chem 108: Class/ Lab Week 12