stable ionic forms | My Assignment Tutor

1) Iron exists as two stable ionic forms Fe2+ and Fe3+. The difference between theseforms of iron is based on a difference in:a) Nuclear chargeb) Atomic numberc) Isotopic abundanced) Number of electronse) Number of neutrons2) According to the following balanced equation, what reaction is represented?N2(g) + 3H2(g)  2NH3(g)a) One molecule of nitrogen reacts with 3 moles of hydrogen gas to produce2 moles of ammonia gas.b) Two molecules of nitrogen gas reacts with 3 molecules of hydrogen gas toproduce 2 molecules of ammonia gas.c) Two g of ammonia gas reacts with 3 g of nitrogen gas to produce 2 g ofammonia gas.d) One mole of nitrogen gas reacts with 3 moles of hydrogen gas to produce2 moles of ammonia gas.e) Cannot tell from the balanced equation alone3) The mass number of the major isotope of Cl containing 18 neutrons isa) 18b) 35c) 36d) 37e) 174) The number of electrons in Cobalt(III) (27Co3+) ion isa) 27b) 26c) 25d) 24e) 305) Use the periodic table to determine which of the following has the largest massa) 1 mole of arsenic (As)b) 1 mole of Chlorine gas (Cl2)c) 0.5 moles Xeon (Xe)d) 3 moles of Nitrogen gas (N2)e) 2 moles of Zinc (Zn)6) N, As3+, P3-, Sb5+ and Bi share the samea) Period of the periodic tableb) The same atomic numberc) The same electron configurationd) The same group of the periodic tablee) None of the above7) The elements of the group VIIa of the periodic table ionise readily by gainingelectrons to form:a) Cationsb) 1+ ionsc) Neutral ionsd) 1- ionse) 2+ ions8) Which of the following has the largest atomic radius, Be, B, C, N, Lia) Beb) Bc) Cd) Ne) Li9) Which element or ion has the electron configuration 1s22s22p63s23p63d8a) Kb) Cac) Ni2+d) Cle) P3-10) 238-Uranium decays spontaneously by alpha emission to 234-thorium. Which ofthe following represents the decay scheme for this process?a) 238U + 1n  238Np + 1p+ 234Th + 4b) 238U  234Th + 4He2+c) 238U  234Th + 4Hed) 234U  234Th + He2+11) The decay of any unstable nuclei occurs via exponential decay at a rate definedby the half life of the element. If the half life of 131I is 9 days, how long does it takefor the chemical amount of 131I to reach 1/8th of the amount present at t = 0a) 9 daysb) 18daysc) 27 daysd) 36 dayse) 42 days12) How many moles of sodium ions are present in 25cm3 of 0.3 M solution ofNaCla) 0.015b) 0.0075c) 7.5d) 15e) .0513) The reaction of iron when it corrodes in oxygenated environments involves theformation of Iron(III) hydroxide. Which of the following equations describes theoverall balanced reaction that occursa) 2Fe + 6H2O  2Fe(OH)3 + 3H2b) 2Fe + H2O +O2  2Fe(OH)3c) 2Fe + 2H2O +O2  2Fe(OH)2d) 2Fe + 3H2O + 1.5O2  2Fe(OH)3e) Fe + 3H2SO4  FeSO4 + 3H214) What mass of Cobalt (II) chloride hexahydrate (CoCl2.6H2O) (molar mass =237.931 g/mol) is required to make 250 mL solution containing 0.3 M Co2+ ionsin solution?a) 12.79 gb) 17.84 gc) 6.39 gd) 75 ge) 51.14 g15) A solution of 1M CoSO4 is used as a stock solution to produce 250 mL of 0.06 MCo2+(aq) ions. How much of the stock solution is required to do this?a) 250 mLb) 15 mLc) 1.25 Ld) 125 mLe) 0.8 L16) If you add a cup of solid table salt (NaCl) to 4 L of boiling water, the salt willdissolve. The reaction can be written asNaCl (s)  NaCl(aq)The water separates the molecules in the salt crystals, and at the same time, thesodium and chloride ions molecules become surrounded by water molecules inthe solution. This quantity of salt will spontaneously dissolve under theseconditions. No solid salt will remain. Which of the following statements regardingthis reaction will NOT be possible?a) The reaction goes to completion.b) The reaction is spontaneous as written.c) The reaction is reversible under the conditions given.d) The products are of lower potential chemical energy than the reactants.e) There is an increase in entropy for the system17) Which of the following intermolecular interactions exist between molecules ofIodinea) Dipole –dipole interactionsb) Dispersion forcesc) Hydrogen bondsd) Ion-ion interactionse) None of the above18) Which one of the following is a solubility property of gasesa) Solubility increases with decreasing pressure.b) Solubility increases with increasing temperature.c) Solubility increases with decreasing temperatured) Gases are insoluble in solutions since like dissolves likee) 22.4 L of gas at 2 atm pressure will contain 1 mole of gas particles19) Which one of the following 0.05 M solutions would most significantly increase theboiling point of water?a) NaCl(aq)b) Al2(NO3)3(aq)c) Ca(NO3)2(aq)d) Ca(OH)2(aq)e) LiF(aq)20) Which of the following options is the equation for a redox reaction?a) H2SO4(aq) +HCO3-(aq)  H2CO3(aq) +HSO4-(aq)b) Ag+(aq) +Cl-(aq)  AgCl(s)c) Mg(OH)2(s) +H2O(l)  Mg(OH)2.H2O(s)d) Cr2O72- + 14H+ + 6e-  2Cr3+ +7H2Oe) CaCO3(s) + H2SO4 (aq) CaSO4(aq) + H2O(l) + CO2(g)21) According to the relationship G = H –TS, a reaction will occur spontaneouslyprovided G is negative. Which one of the following options is a spontaneousreaction? (all at 25°C)a) H = 10.5 kJ kJ/mole and S = -30 J K.mol-1b) H = 1.8 kJ/mole and S = -113 J K.mol-1c) H = -25 kJ/mole and S = -250 J K.mol-1d) H = 0.56 kJ/mole and S = 2 J K.mol-1e) H = -0.56 kJ/mole and S = -2.5 J K.mol-122) According to the table of standard electrode potentials below, which of thefollowing metals (M) when added to a solution of Nickel(II) sulphate will displaceNickel from solution causing it to precipitate according to the equation Ni2+(aq) +M(s)  Ni(s) + M2+(aq). Ni2+ + 2e-  NiPb2+ +2e-  PbHg2+ + 2e-  HgSn2+ +e-  SnCu2+ + 2e-  CuFe2+ + 3e-  Fe-0.25 v-0.13 v0.85 v-0.14v0.13 v-0.44 v a) Pbb) Hgc) Snd) Fee) Cu23) Increasing amounts of an ionic salt such as NaCl is dissolved in water until thesolubility limit is reached. Which of the following statements is NOT trueregarding the reaction taking place in the beakera) The dissolution reaction stopsb) The reaction reaches equilibriumc) The Free energy for the reactions in the vessel is zero kJ mol-1d) The amount of salt in solid form stays constante) Increasing the amount of water in the vessel disturbs the equilibrium andmore salt dissolves24) On the molecular level, an increase in the temperature of a substance isaccompanied by:a) An increase in the chemical potential of the substanceb) An increase of the heat capacity of the substancec) An Increase in the Exothermic behaviourd) A spontaneous reactione) An increase in average kinetic energy of the substance25) The production of ammonia via the Haber process 2N2 + 3H2  2NH3 is anexothermic process. Which of the following will be true of the reactiona) Increasing the temperature of reaction pushes the equilibrium to the leftb) A fast processc) It is an entropy-driven reaction.d) A spontaneous process at room temperaturee) One in which the temperature of the reaction remains unchanged(isothermal)26) In which one of the following does chlorine have an oxidation number of -1?a) ClOb) Clc) ClO3-d) ClO4-e) Cl227) Which one of the following statements applies to the following redox reaction?ClO- + 2I- + 2H+  Cl- + H2O + I2a) Chlorine in hypochlorite is oxidized and Iodine is the oxidizing agent.b) Chlorine in hypochlorite is reduced and Iodide is the reducing agent.c) Chlorine in hypochlorite is reduced and Iodide is the oxidizing agent.d) Iodide is reduced and hypochlorite is the reducing agente) Neither element if oxidized28) If free energy is the term that determines whether a reaction proceedsspontaneously or not, what value must the free energy of a reaction have in orderto proceed spontaneouslya) Impossible to tellb) >0 kJ/molc) 0 kJ/mold) CH3COOH + H2Od) CH3COO- + H2O- —> CH3COOH + HO53) The Table below lists some acids and their pKa values at 25oC. AcidpKaH3PO42.1H2CO36.1H2PO4-7.1HOBr8.6NH4+9.2 Which of the following chemical species in the table above would you use as theacidic component of a buffer to keep a solution at a pH around 8.3?a) H3PO4b) H2CO3c) H2PO4-d) HOBre) NH4+The titracid, H54) Thconation curvA, with 0.5e pKa oftinuous lina) 0.0b) 22.5c) 8.1d) 4.5e) 2.8e resulting000 M Nathe monoe ( —— ),from a stuOH solutioprotic acican be esdent titratn is showd HA titratimated toing 25.00n below –ted withbe close tmL of an uNaOH, aonknown ws showneakby the55) With the data provided above, and using data from the titration curve, calculatethe initial concentration of the monoprotic acid, HA ( —— ), before any 0.500 MNaOH was added.a) 0.0733 mol L–1b) 0.100 mol L–1c) 0.127 mol L–1d) 0.450 mol L–1e) 0.174 mol L–1Draw the structure of the products of the following reactions:56)OHO+ HOa)OHOOHb)O–OHOHc)O–Od)OHOHO57)OHO+OHH+heata)OOb)OOOc)Od)OOHOH58)OOHOheata) OHOHHO+b) OHOH+c) HOHO+d) OHOHO+59)HN+ H O3+a)HNOH+ 2b)HN+OHc) NH2+d) NOH+ 260)OHKMnO4H+a) OK b)OHOc)OHOH d) OMnO4END OF THE EXAMINATION PAPER