Chem 122 Exam 2 Questions for Saturday Morning Review Spring 2022 R Hatfield L Schroeder and E Stec 1 Determine the volume of H2S at 800 K and 645 torr needed to produce 35 0 g of Fe2S3 Assume that there is excess FeCl3 present 2 FeCl3 aq 3 H2S g Fe2S3 s 6 HCl aq 39 1 L 2 How many grams of CO2 are formed at STP when 32 0 L of C2H6 are burned in excess oxygen gas 2 C2H6 g 7 O2 g 4 CO2 g 6 H2O g 126 g 3 Calculate the volume in L of H2 g at 30 1 C and 0 85 atm that can be formed when 275 mL of 0 725 M HCl solution reacts with excess Mg 2 9 L Mg s 2HCl aq MgCl2 aq H2 g Follow up Identify the oxidizing and reducing agents for this reaction 4 Oxygen gas placed in a container having a pinhole opening in its side leaks from the container 1 49 times faster than does an unknown gas placed in the same apparatus What is the molar mass of unknown gas 71 04 g mol Follow up Suppose it takes 2 0 min for a given volume of oxygen to effuse How long will it take for the same volume of the unknown gas to effuse 2 98 min 5 What is the root mean square speed of Xe gas atoms at 21 236 m s Follow up If the temperature increased would the rms decrease or increase 6 Predict products of the following reactions a SnCl2 s Pb s b AgClO4 aq Mg s 1 7 Give the molecular total and net ionic equation for the reaction if any that occurs when aqueous solutions of FeSO4 and Na3PO4 are mixed 8 Iodide is made by the following reaction 2 NaIO3 aq 5 NaHSO3 aq 3 NaHSO4 aq 2 Na2SO4 aq H2O l I2 aq a What mass of I2 can be obtained if you mixed 15 0 g of NaIO3 with 125 mL of 0 853 M NaHSO3 5 41 g 3 03 g b If the percent yield for this reaction was 56 find the actual yield in grams of I2 9 A gas mixture contains three gases A B and C If the total pressure of the gas mixture is 224 atm and the partial pressure of gas A is 103 atm what is the mole percentage of gas A in the mixture 46 0 10 Phosphoric acid is a A strong electrolyte B weak electrolyte C nonelectrolyte 11 A solution of 0 50 M acetic acid is poured over 5 00 g of solid sodium carbonate a How many milliliters of acetic acid is needed to react with all of the sodium carbonate 190 ml b How many moles of gas form in this reaction 0 0472 mol c What is the volume of this gas at STP 1 06 L 2