4. In a reaction of 15g of Solid Iron with excess Chloride gas, what is the largest possible amount of Iron(III) Chloride that could be obtained?

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1 Form Code X NAME CHM 1025, Spring 2018 Final Packet Instructions: Do your best and don t be anxious. Read the question, re-read the question, write down all given or valuable information, and write down what you want to find. As on all graded events, the loving of moles applies. 1. Suppose you had excess HCl and you wanted to make 1L of H2O. Given that the density of water is 1g/1mL, how many grams of NaOH would you need? g g 3. 22,197g g 2. Why does sodium always naturally occur as a monovalent cation (Na + ) in compounds? 1. its electronegativity is too large 2. its 1st ionization energy is too large 3. its 2nd ionization energy is too large 4. its 1st electron affinity is too large 5. its 2nd electron affinity is too large 3. The overall reaction in the commercial heat pack can be represented as 4 Fe(s) + 3O2(g) 2Fe2O3(s) ΔH = 1652 kj How much heat is released when 100. g Fe and 200. g O2 are reacted? kj kj kj kj kj

2 4. In a reaction of 15g of Solid Iron with excess Chloride gas, what is the largest possible amount of Iron(III) Chloride that could be obtained? g g g g 5. Suppose a chemist has 10g of potassium chloride (MW 74.55) and 10g of silver acetate (MW ). What is the theoretical yield of silver chloride she could produce? g g g g 6. Select the false statement below: (1) Pb 2+ (aq) + 2I (aq) PbI2(s) is a precipitation reaction but is not a redox reaction (2) CH4(g) + 2O2(g) CO2(g) + 2H2O(g) is a combustion reaction and a redox reaction (3) Ca(s) + F2(g) CaF2(s) is a precipitation reaction and a redox reaction (4) HNO3(aq) + KOH(aq) H2O(l) + KNO3(aq) is an acid-base reaction but is not a redox reaction (5) H2SO4(aq) + Ba(OH)2(aq) 2H2O(l) + BaSO4(s) is a precipitation reaction and an acidbase reaction 7. Name the Period 3 element with the following successive ionization energies (in kj/mol): 1. Si 2. P 3. S 4. Cl 5. Ar IE1 IE2 IE3 IE4 IE5 IE ,230

3 8. If you dropped a 1 gram chunk of either iron (heat capacity = J/gK) or gold (heat capacity = J/gk) at 100 C into 1 gram of water at 25 C, which metal would change the water temperature most and is the water temperature change endothermic or exothermic? (1) Iron, water temperature change is exothermic (2) Iron, water temperature change is endothermic (3) Gold, water temperature change is exothermic (4) Gold, water temperature change is endothermic (5) Both are the same, water change is endothermic 9. By how many electrons does an atom get reduced in the following reaction? KClO3 + HBr Br2 + H2O + KCl (1) one (2) two (3) five (4) six (5) seven

4 10. Which of the following is true a. % yield = ( actual theoretical ) * 100 b. The theoretical yield exists only on paper (i.e. it never truly exists) c. If you have two different values of reactants, the limiting reactant s product value is the actual value and the excess reactant s product value is the theoretical d. A 100% percent yield is possible to obtain 1. a, b, and d only 2. a, b, and c only 3. a and c only 4. all of the above 5. none of the above 11. The Citric Acid Cycle is a fundamental biochemical reaction used by all aerobic organisms where stored energy is released through the oxidation of acetyl-coa. This cycle consists of ten different steps. The very first step of the citric acid cycle is called citrate synthase. Here, acetyl-coa undergoes a type of reaction called Claisen Condensation with oxaloacetate and water. The reaction produces a substance called citrate. The reaction for citrate synthase is shown below. C23H38N7O17P3S + C4H4O5 + H2O = C21H36N7O16P3S + C6H8O kJ/mol Given the equation, what is true about this reaction? 1. The rxn is endothermic and delta H will be negative. 2. The rxn is endothermic and delta H will be positive. 3. The rxn is exothermic and delta H will be negative. 4. The rxn is exothermic and delta H will be positive. 5. The rxn is endothermic and delta H will be zero.

5 Question numbers all refer to the following unbalanced equation and formula weight (FW) data: Pb(C2H3O2)2(aq) + NH4Br(aq) PbBr2(s) + NH4C2H3O2(aq) FW s (g/mol) What is the sum of the coefficients of the balanced equation? (1) 4 (2) 6 (3) 8 (4) 10 (5) None of the Above 13. If g NH4Br and g Pb(C2H3O2)2 are dissolved and allowed to react, what is the theoretical yield of PbBr2? (1) g (2) g (3) g (4) g (5) g

6 Questions will be based on the paragraph and reaction below. Blackpowder (black gunpowder) was first invented in China during 850 A.D. It was first weaponized by the Ottomans in 1350 through the use of cannons. It remained the only known chemical explosive up until 1884, when Paul Vieille invented the first successful form of smokeless powder. The ignition of gunpowder creates gases which propel the projectile forward. A simplified balanced equation for the ignition of gunpowder is seen below. 6 KNO 3 + C 7H 4O + 2 S K 2CO 3 + K 2SO 4 + K 2S + 4 CO CO + 2 H 2O + 3 N 2 Additionally, the mass proportions by weight of gunpowder are 75% potassium nitrate (known as saltpeter or saltpeter), 15% softwood charcoal (C7H4O), and 10% sulfur. 14. Now, suppose a solider of the 69 th New York Volunteer Infantry fires a cartridge from his issued US Model 1842 Musket during the battle of Gettysburg. Additionally, the average cartridge holds approximately 8.42 grams of black powder. Given this information, what is the maximum amount of Carbon Dioxide gas capable of being produced after ignition? g g g g 15. Gunpowder when ignited produces massive amounts of energy. This amount of energy can be affected by outside elements such as rain. The year is 1862 and General George B McLellan has started his Peninsular Campaign towards Richmond. Now, suppose a Zouave from the 5 th New York Infantry fires his Model 1861 Springfield during a rainy day on the campaign. Due to the rain some of the powder gets wet and only 65% of the gunpowder ignites. Calculate the actual amount of energy in kilojoules that was produced given that the energy density of gunpowder is 3 MJ/1kg kj kj 3. 16,419 kj 4. 25,260 kj

7 16. The main problem with black powder is that it is corrosive and firing blackpowder produces water which if left unattended will corrode the inside of the gun barrel. Suppose that a private of the 75 th Ohio Mounted Infantry fires his Model 1861 Springfield during the Battle of Gainesville which occurred on August 17 th After the battle the private forgets to clean his rifle. Suppose he fired a total of fifteen cartridges during the battle. Assuming that all the cartridges have excess saltpeter, and each cartridge holds approximately g charcoal and g sulfur, what is the maximum amount of water that could be in the barrel? g g g g 17. Now, suppose that the soldier went to clean his rifle after the battle and that some of the water evaporated due to the heat in Florida. Suppose that only 5.23g of water was present in the barrel. With this information, what is the percent yield of the water from the ignition? 1. 80% 2. 74% 3. 66% 4. 63%

8 18. Rank the following five ions in order of increasing ionic radius: Rb +, In 3+, Al 3+, Sr 2+, Ga 3+ 1) Rb + < Ga 3+ < In 3+ < Sr 2+ < Al +3 2) Al 3+ < Rb + < Ga 3+ < In 3+ < Sr 2+ 3) Al 3+ < Ga 3+ < In 3+ < Sr 2+ < Rb + 4) In 3+ < Sr 2+ < Rb + < Al 3+ < Ga 3+ 5) Ga 3+ < Al 3+ < Sr 3+ < In 2+ < Rb Which of the following ground-state electron configurations corresponds to an atom that has the most negative value of the electron affinity (the greatest affinity for electrons)? a) 1s2 2s2 2p6 3s1 b) 1s2 2s2 2p6 3s2 3p5 c) 1s2 2s2 2p6 3s2 3p2 d) 1s2 2s2 2p6 3s2 3p6 3d5 4s2 e) 1s2 2s2 2p6 GOOD LUCK and SMILE ON THE EXAM!!!