General Chemistry 120 Spring 2022 Exam 6 Acid equilibrium constants 7 2x10 4 Ka for HF Ka for acetic acid CH3COOH 1 80x10 5 4 0x10 10 Ka for HCN 5 55x10 10 Ka for NH4 Ka for formic acid HCOOH 1 78x10 4 Solubility products Ksp for BaSO4 s 1 1x10 10 Ksp for PbCl2 s 1 7x10 5 Ksp for PbSO4 s 2 5x10 8 Ksp for Ag2CrO4 s 9 0x10 12 Ksp for AgCN s 6 0x10 17 Ksp for MnCO3 2 3x10 11 Ksp for Mg OH 2 5 6x10 12 Ksp for AgBr 5 4x10 13 Ksp for AgCl 1 6x10 10 Ksp for Sr SO4 3 8x10 7 Thermodynamic Quantities Substance C graphite Ca s Ca OH 2 CH3OH l C6H12O6 CO2 g CO g CS2 g H2 g H2O g H2S g H2SO4 l NO g NO2 g O2 g O3 g S s SO2 g 296 8 SO3 g 395 8 0 0 986 09 238 4 1275 394 110 5 116 7 0 242 20 6 814 90 34 0 143 0 Energy Constant R 8 314 J mol K 5 6 41 59 83 127 2 212 214 197 7 237 8 130 7 189 205 8 156 9 211 240 205 1 239 32 1 248 2 256 8 Question 1P T F negative The entropy change for a spontaneous chemical reaction cannot be Question 2P T F Viewed informally work is concentrated energy while heat is dissipated energy Question 3P T F degrees Kelvin According to the third law of thermodynamics there is no entropy at zero Question 4P T F Work energy from a reaction that is exergonic can be harnessed and used Question 5P T F The concentration of a salt that can dissolve at equilibrium is called its solubility Question 6P T F of base The solubility of Mg3 PO4 2 could be increased by adding a small amount rxn is negative and G is positive for particular conditions the reaction will occur The First Law of Thermodynamics states that energy cannot be converted from one The heat generated by a system can only be used to do work if there is a temperature If G0 Question 7P Which of the following statements are correct I spontaneously under those conditions II form to another III gradient A B C D E All statements are correct Only statements I and II are correct Only statements II and III are correct Only statement III is correct None of the statements is correct 2 in solution A student added 0 223 grams of Ag2CrO4 to water such that the final Question 8P Ag2CrO4 Mol wt 332 gm mol dissolves to form silver ions Ag and chromate ions CrO4 volume was 775 mL What will be the concentration of silver ions at equilibrium in M A B C D E 1 31x10 4 2 62x10 4 8 67x10 4 6 72x10 4 1 31x10 5 Question 9P Referring to the previous problem how many grams of Ag2CrO4 will remain undissolved at equilibrium A B C D E 0 223 0 222 0 189 0 096 0 001 Question 10P G0 67 kJ mol for the reaction 2H2S g SO2 g 3S s 2H2O g at 25 C Find G in kJ mol for the same reaction when PH2S 1 10 3 bar PSO2 1 10 2 bar PH2O g 3 10 4 bar and 2 31 grams of solid sulfur are at equilibrium at 25 C A B C D E 0 72 4 54 5380 61 5 Question 11P What is G0 in KJ mol at 25 C for the reaction A B C D E 5 55x109 2 41x104 4460 55590 55 6 Question 12P You and your friend who didn t take Chem 120 are each given a 55 liter drum of 20 0 M AgCl Your friend pours off the liquid and collects the solid AgCl at the bottom You first add 1 Kg of NaCl mix it and let it reach equilibrium before pouring off the liquid and collecting the solid AgCl How many more grams of AgCl did you collect A B C D E 1 24 g 0 94 g 0 24 g 0 10 g 0 01 g