Last Name First Name ID Please record your answers on the answer sheet using a 2 pencil You may use the Exam booklet for calculations but only the answer sheet will be scored 1 I pledge that I have neither given nor received help on this exam Exam 1 Code 111 2 How many grams of chromium Cr are found in 1 00 x 102 g of potassium dichromate K2Cr2O7 Cr 52 00 g mol O 16 00 g mol 3 For which reaction is DH most nearly equal to DE A 3H2 g N2 g 2NH3 g B Cl2 g H2 g 2HCl g C CO2 l CO2 g D 2SO2 g O2 g 2SO3 g 4 2 5 g of Al react with 7 2 g of Fe2O3 according to the reaction below How many grams of Fe are produced 2 Al s Fe2O3 s Al2O3 s 2 Fe s Fe 55 85 g mol Al 26 98 g mol O 16 00 g mol A True B False K 39 10 g mol A 12 2 g B 17 7 g C 24 3 g D 35 4 g A 5 0 g B 0 87 g C 2 5 g D 5 2 g 5 What is the coefficient for H2O l when the equation is balanced with smallest integer coefficients Br2 l OH aq Br aq BrO3 aq H2O l A 12 B 3 C 18 D 6 6 For the reaction CH3Cl g HCl g CH4 g Cl2 g what is the value of DH rxn kJ mol kJ mol Bond Dissociation Energy 413 C H C Cl 328 Cl Cl 242 H Cl 431 A 104 kJ mol B 274 kJ mol C 274 kJ mol D 68 kJ mol 7 Which of the following statements is are CORRECT 1 A system is defined as an object or collection of objects being studied 2 Surroundings are defined as the entire universe including the system 3 In an endothermic reaction heat is transferred from the system to the surroundings A 1 only B 2 only C 3 only D 1 and 3 Page 2 Last Name First Name ID 8 What volume of 18 0 M sulfuric acid must be diluted to 250 0 mL to afford a 0 55 M solution of 9 Which element is a solid at 25 C and 1 atm pressure 10 Commercial cold packs consist of solid ammonium nitrate NH4NO3 and water NH4NO3 absorbs 25 69 kJ of heat per mole when dissolved in water In a coffee cup calorimeter 5 60 g NH4NO3 is dissolved in 100 0g of water at 22 0 C What is the final temperature of the solution Assume that the solution has a specific heat capacity of 4 18 J g C 11 Which definition is INCORRECT A mole fraction moles of solute molues of solution B ppm volume of solute 109 volume of solution C weight percent grams of solute 100 grams of solution D molality moles of solute kilogram of solvent Page 3 sulfuric acid A 3 1 mL B 7 6 mL C 4 5 mL D 31 mL A Fluorine B Chlorine C Iodine D Bromine A 0 0 C B 17 9 C C 26 1 C D 11 6 C 12 Which of the following process es is are endothermic 1 the combustion of hydrogen 2 the condensation of water 3 the evaporation of isopropyl alcohol 13 Which aqueous solution has the highest boiling point A 1 only B 2 only C 3 only D 1 and 3 A 0 30 m C2H5OH B 0 25 m KNO3 C 0 20 m CaBr2 D 0 10 m FeCl3 Mg 24 31 g mol A Mg2P4O7 B Mg H2PO4 2 C MgNH4PO4 D Mg3 PO4 2 A 0 050 mol B 0 024 mol C 0 0080 mol D 0 20 mol 14 Which compound contains the highest percentage of magnesium by mass H 1 01 g mol N 14 01 g mol P 30 97 g mol O 16 00 g mol 15 Ideally colligative properties depend only on the A partial pressure of the gases above the surface of a solution B molar masses of the solute particles in a solution C relative numbers of solute and solvent particles in a solution D density of a solution 16 How many moles of nitrate anions NO3 are in 20 mL of 0 40 M Al NO3 3 Page 4 Last Name First Name ID 17 Determine the enthalpy change for the reaction of iron with oxygen 2 Fe s 3 2 O2 g Fe2O3 s given the thermodynamic equations below Fe s 3 H2O l Fe OH 3 s 3 2 H2 g H2 g O2 g H2O l Fe2O3 s 3 H2O l 2 Fe OH 3 s DH 160 9 kJ mol DH 285 8 kJ mol DH 288 6 kJ mol 18 What is the mole fraction c of CH3OH in an aqueous solution that is 12 0 m in CH3OH C 12 01 g mol H 1 01 g mol O 16 00 g mol A 824 2 kJ mol B 252 6 kJ mol C 163 6 kJ mol D 32 2 kJ mol A 0 667 B 0 216 C 0 400 D 0 178 A C3H4O4 B C2HO5 C C2H4O3 D C2H4O6 19 Which of the following is NOT an empirical formula 20 The enthalpy change for which reaction represents the standard enthalpy of formation DH f for hydrogen cyanide HCN A H2 g C s N2 g HCN g B H g C s N g HCN g C H2 g 2C s N2 g 2 HCN g D H aq CN aq HCN g Page 5 21 Complete combustion of 1 00g of a hydrocarbon gives 3 38 g carbon dioxide What is the empirical formula of the molecule C 12 01 g mol H 1 01 g mol O 16 00 g mol 22 A mass of 0 4113 g of an unknown acid HA is titrated with NaOH If the acid reacts with 28 10 mL of 0 1055 M NaOH aq what is the molar mass of the acid 23 Calculate the enthalpy change for the following reaction at 25 C The value of DH f in kJ mol is A C2H5 B C3H8 C CH2 D CH A 9 128 g mol B 337 3 g mol C 820 7 g mol D 138 7 g mol given below each species Al3 aq 3 OH aq Al OH 3 s 531 230 0 1276 A 2040 kJ mol B 515 kJ mol C 55 kJ mol D 975 kJ mol Page 6 Last Name First Name ID 24 Use the standard heats of formation to estimate the Ti Cl bond energy DTi Cl in TiCl4 Heat of Formation DH f Cl g Cl2 g Ti g TiCl4 g 121 7 kJ mol 0 0 kJ mol 468 kJ mol 763 4 kJ mol A 307 kJ mol B 338 kJ mol C 430 kJ mol D 1718 kJ mol A 2 B 3 …