CHEM 121 Final Exam Practice Problems for Part I KEY 1 Provide the correct name or formula for each the following compounds a K2CrO4 potassium chromate e carbon tetrachloride CCl4 b N2O5 dinitrogen pentoxide f silver nitrate AgNO3 c Pb CO3 2 lead IV carbonate g sodium phosphide Na3P d HgS mercury II sulfide h sulfuric acid H2SO4 aq 2 For each of the following i Identify the type of reaction using the letters designated below Combination C Double Replacement Precipitation P Decomposition D Acid Base Neutralization N Single Replacement SR Combustion B TYPE ii Balance the equation S a 2 Al s N b 3 NaOH aq H3PO4 aq P c K2CrO4 aq Mg NO3 2 aq MgCrO4 s D d 2 3 Cu NO3 2 aq 3 3 Cu s 2 Al NO3 3 aq H2O l Na3PO4 aq 2 KNO3 aq LiHCO3 s Li2CO3 s H2O g CO2 g 3 For each of the following sets of reactants write NR for no reaction OR write the formulas for the products including physical states and balance the equation if a reaction occurs a b 2 Zn s 2 LiOH aq c C5H12 l d HNO3 aq e Mg s HCl aq H2 g H2SO4 aq 8 O2 g KHCO3 aq H2O l CHEM 121 Final Exam Practice Problem Key ZnCl2 aq 2 H2O l Li2SO4 aq 5 CO2 g 6 H2O g H2O l CO2 g KNO3 aq NR Mg is not an active metal p 1 Nuclear Chemistry Practice Problems 1 The inhalation of radon 222 and its decay to form other isotopes poses a health hazard Write balanced nuclear equations for the decay of radon 222 to lead 206 in eight steps a Step 1 Radon 222 decays by alpha emission Radon has the element symbol Rn 222 86 4 2 Rn 218 84 b Step 2 The daughter product in part a decays by alpha emission c Step 3 The daughter product in part b decays by beta and gamma emissions 214 82 Pb d Step 4 The daughter product in part c decays by beta and gamma emissions 214 83 Bi 218 84 Po Po 4 2 214 82 Pb 00 21483 Bi 0 1 00 21484 Po 0 1 e Step 5 The daughter product in part d decays by beta emission 214 84 Po f Step 6 The daughter product in part e decays by alpha emission 214 85 At g Step 7 The daughter product in part f decays by beta and gamma emissions 210 83 Bi h Step 8 The daughter product in part g decays by alpha and gamma emissions 210 84 Po 0 1 4 2 214 85 210 83 At Bi 00 21084 Po 0 1 4 2 20682 Pb 0 0 The final stable isotope is lead 206 General Practice Problems 2 Indicate the number of protons neutrons and electrons in the following isotopes phosphorus 32 iodine 131 oxygen 18 Rn 222 chromium 51 fluorine 21 potassium 40 copper 64 Isotope Atomic Symbol of protons of neutrons of electrons 15 17 15 I 53 78 53 O 8 10 8 phosphorus 32 32 15 iodine 131 131 53 oxygen 18 18 8 P Rn 222 222 86 Rn 86 136 86 chromium 51 51 24 Cr 24 27 24 F 9 12 9 K 19 21 19 Cu 29 35 29 fluorine 21 21 9 potassium 40 40 19 copper 64 CHEM 121 Final Exam Practice Problem Key 64 29 p 2