Free NEET Chemistry multiple-choice questions on Redox Reactions. Attempt each question and reveal the answer with a full explanation.
The oxidation number of phosphorus in H 4P 2O 7 is: +5 +3 +4 +6 The oxidation state of nitrogen in magnesium nitride ( Mg 3N 2 ) is: -3 +3 +5 0 In the balanced redox reaction BrO 3 - + 5Br - + 6H + 3Br 2 + 3H 2O , the oxidation state of bromine in BrO 3 - changes to: 0 +3 +1 +2 The average oxidation state of iron in the non-stoichiometric compound Fe 0.94 O is approximately: +2.13 +2.00 +0.94 +3.00 In the reaction Cl 2 + 2NaOH (hot and conc.) NaCl + NaClO 3 + H 2O , the oxidation state of chlorine changes from 0 to: -1 and +5 -1 and +1 -1 and +3 0 and +5 Which of the following is the oxidation state of Xenon in H 4XeO 6 ? +8 +6 +4 +2 The number of electrons involved in the oxidation of one mole of hydrazine ( N 2H 4 ) to nitrogen gas ( N 2 ) is: 4 2 6 1 In the process of electrochemical corrosion (rusting), the reduction reaction occurring at the cathodic site in the presence of acidic environment is: O 2(g) + 4H +(aq) + 4e - 2H 2O(l) Fe 2+ (aq) + 2e - Fe(s) 2H 2O(l) + 2e - H 2(g) + 2OH -(aq) Fe(s) Fe 2+ (aq) + 2e - For the redox reaction KMnO 4 + H 2O 2 + H 2SO 4 MnSO 4 + K 2SO 4 + O 2 + H 2O , the molar ratio of KMnO 4 to H 2O 2 in the balanced equation is: 2:5 5:2 1:1 2:3 When KMnO 4 reacts with sulfur dioxide in aqueous solution, the products formed are: Mn 2+ and SO 4 2- MnO 2 and S Mn 2+ and S MnO 4 2- and SO 3 2- What are the individual oxidation states of the three iodine atoms in the triiodide ion ( I 3 - )? 0, 0, -1 -1/3, -1/3, -1/3 +1, -1, -1 0, -1, -1 During the disproportionation of phosphorous acid ( H 3PO 3 ) upon heating, the oxidation states of phosphorus in the products are: -3 and +5 +1 and +5 0 and +5 -3 and +3 For the reaction Fe 2O 3 + 3CO 2Fe + 3CO 2 , which statement is correct? Fe 2O 3 is the oxidizing agent CO is the oxidizing agent Fe 2O 3 is reduced to CO 2 The oxidation state of C changes from +4 to +2 What is the oxidation state of the central Bromine atom in tribromine octoxide ( Br 3O 8 )? +4 +6 +16/3 +2 Which of the following describes a 'Comproportionation' reaction? Ag 2+ (aq) + Ag(s) 2Ag +(aq) 2H 2O 2(l) 2H 2O(l) + O 2(g) Cl 2(g) + 2OH -(aq) Cl -(aq) + ClO -(aq) + H 2O(l) Zn(s) + CuSO 4(aq) ZnSO 4(aq) + Cu(s) The equivalent weight of Na 2S 2O 3 (Molar mass = M ) in the reaction with I 2 to form Na 2S 4O 6 is: M M/2 M/4 2M How many moles of K 2Cr 2O 7 are required to oxidize 1 mol of Sn 2+ to Sn 4+ in acidic medium? 1/3 mol 3 mol 1/6 mol 1/2 mol What is the average oxidation state of Nitrogen in NH 4NO 2 (ammonium nitrite)? 0 -3 +3 +1 What is the oxidation state of iodine in the interhalogen ion ICl 2 - ? +1 +3 +5 +7 In the following balanced chemical reaction, 8MnO 4 - + 3S 2O 3 2- + H 2O 8MnO 2 + 6SO 4 2- + 2OH - , the change in the oxidation state of sulfur is: From +2 to +6 From +4 to +6 From +2 to +4 From +1 to +6 When copper reacts with dilute nitric acid ( HNO 3 ), the gaseous product formed is: Nitric oxide ( NO ) Nitrogen dioxide ( NO 2 ) Nitrous oxide ( N 2O ) Ammonia ( NH 3 ) The oxidation state of carbon in hydrogen cyanide ( HCN ) is: +2 +4 0 +1 In the electrochemical process of rusting, the reaction occurring at the cathodic site is: O 2(g) + 4H +(aq) + 4e - 2H 2O(l) Fe(s) Fe 2+ (aq) + 2e - Fe 2+ (aq) Fe 3+ (aq) + e - 2H 2O(l) O 2(g) + 4H +(aq) + 4e - The equivalent weight of potassium permanganate ( KMnO 4 ) in acidic medium is (where M is the molar mass): M / 5 M / 3 M / 1 M / 6 When chlorine gas reacts with cold and dilute sodium hydroxide, the products formed are: NaCl and NaClO NaCl and NaClO 3 NaClO and NaClO 3 NaCl and Cl 2O The oxidation state of oxygen in potassium ozonide ( KO 3 ) is: -1/3 -1/2 -1 0 The additional voltage required to maintain a specific rate of electrode reaction over the reversible potential is known as: Overpotential Standard potential Decomposition potential Liquid junction potential In the reaction between iodine and sodium thiosulfate, I 2 + 2Na 2S 2O 3 2NaI + Na 2S 4O 6 , the iodine is: Reduced and acts as an oxidizing agent Oxidized and acts as a reducing agent Reduced and acts as a reducing agent Oxidized and acts as an oxidizing agent The number of moles of KMnO4 reduced by one mole of KI in alkaline medium is :- One Two Five One fifth Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true? The G f of the sulphide is greater than those for CS2 and H2S . The G f is negative for roasting of sulphide ore to oxide. Roasting of the sulphide to the oxide is thermodynamically feasible. Carbon and hydrogen are suitable reducing agents for metal sulphides. The number of moles of KMnO4 that will be needed to react with one mole of sulphite ion in acidic solution is 4/5 2/5 1 3/5 The pair of compounds that can exist together is:- Mg, 0.16 g O2 , 0.16 g Mg, 0.44 g O2 , 0.28 g The pair of compounds that can exist together is:- FeCl3, SnCl2 HgCl2, SnCl2 FeCl2, SnCl2 FeCl3, KI (a) H2O2 + O3 -> H2O + 2O2 (b) H2O2 + Ag2O -> 2Ag + H2O + O2 Role of hydrogen peroxide in the above reactions is respectively - Oxidizing in (a) and reducing in (b) Reducing in (a) and oxidizing in (b) Reducing in (a) and (b) Oxidizing in (a) and (b) In the complex [Cr(H 2O) 6]Cl 3 , the oxidation state of the central metal atom chromium is: +3 +2 +6 0 Which of the following statements is incorrect? Lyophilic sols are more stable than lyophobic sols In coagulation of a negative sol, flocculating power is in the order of Al 3+ > Ba 2+ > Na + In the flocculation of a positive sol, flocculating power is in the order, Cl - > SO4 2- > PO4 3- > [Fe(CN)6] 4- Lyophilic colloids have greater affinity for solvents For the redox reaction MnO4 - + C2O4 2- + H+ -> Mn 2+ + CO2 + H2O The correct coefficients of the reactants for the balanced equation are 2 16 5 2 5 16 16 5 2 5 16 2 Which of the following reactions are disproportionation reaction? (a) 2Cu+ -> Cu 2+ + Cu 0 (b) 3MnO4 2- + 4H+ -> 2MnO4 - + MnO2 + 2H2O (c) 2KMnO4 K2MnO4 + MnO2 + O2 (d) 2MnO4 - + 3Mn 2+ + 2H2O -> 5MnO2 + 4H+ Select the correct option from the following (a) and (d) only (a) and (b) only (a), (b) and (c) (a), (c) and (d) Given below are two statements Statement I: In the coagulation of a negative sol, the flocculating power of the three given ions is in the order Al 3+ > Ba 2+ > Na+ Statement II: In the coagulation of a positive sol, the flocculating power of the three given salts is in the order NaCl > Na2SO4 > Na3PO4 In the light of the above statements, choose the most appropriate answer from the options given below Both Statement I and Statement II are incorrect. Statement I is correct but Statement II is incorrect. Statement I is incorrect but Statement II is correct. Both Statement I and Statement II are correct. On balancing the given redox reaction, a Cr2O7 2- + b SO3 2- (aq) + c H+ (aq) 2a Cr 3+ (aq) + b SO4 2- (aq) + c 2 H2O (l) the coefficients a, b and c are found to be, respectively- 1, 3, 8 3, 8, 1 1, 8, 3 8, 1, 3 The oxidation number of sulfur in peroxomonosulphuric acid ( H 2SO 5 , Caro's acid) is: +6 +8 +4 +2 The oxidation number of iron in the brown ring complex [Fe(H 2O) 5(NO)]SO 4 is: +1 +2 +3 0 Given that E Fe 3+ /Fe 2+ = 0.771 V and E Fe 2+ /Fe = -0.441 V , the standard electrode potential for the half-cell reaction Fe 3+ + 3e - Fe(s) is: -0.037 V +0.330 V +1.212 V -0.111 V Which of the following is the oxidation state of Carbon in C 3O 2 (Carbon suboxide)? +4/3 (average) +2/3 +2 +4 What are the oxidation states of the two sulfur atoms in the thiosulfate ion ( S 2O 3 2- )? +6 and -2 +4 and 0 +2 and +2 +5 and -1 Which of the following describes the relationship between the resistance ( R ) and the dimensions of an electrolytic conductor? R = (l / A) R = (A / l) R = G (l / A) R = (A / l) The number of moles of KMnO 4 reduced by 1 mol of KI in alkaline medium is: 1 2 5 1/5 The number of moles of KMnO 4 required to oxidize 1 mole of ferrous oxalate ( FeC 2O 4 ) in acidic medium is: 0.6 1.5 1.0 1.2 What is the stoichiometric ratio of MnO 4 - to SO 2 in the balanced redox reaction occurring in an acidic medium? 2 : 5 1 : 1 5 : 2 2 : 3 The n -factor of K 2Cr 2O 7 in an acidic medium is 6. What is its n -factor in a strongly basic medium where it converts to CrO 4 2- ? 0 3 6 1 In the reaction FeS 2 + O 2 Fe 2O 3 + SO 2 , what is the n -factor (valence factor) for FeS 2 ? 11 10 1 5 In the balanced equation for the oxidation of ethanol by acidified K 2Cr 2O 7 to acetic acid, the ratio of moles of ethanol to K 2Cr 2O 7 is: 3:2 2:3 1:1 3:1 Considering Ellingham diagram, which of the following metals can be used to reduce alumina? Mg Zn Fe Cu The correct decreasing order of oxidation state of the underlined atom in each molecule is P 4 O 10 > S O 3 > H 2 O N 2 O 5 > Al 2 O 3 > H 2 S Pb O 2 > N 2 O 3 > S O 3 P 4 O 6 > Cl 2 O 7 > Al H 3 Based on the electrochemical series, which of the following metals can displace iron from an aqueous solution of FeSO 4 ? Zinc Copper Silver Gold The number of electrons involved in the reduction of one mole of MnO 4 - to Mn 2+ is: 5 2 3 7 Comparing the standard reduction potentials of the halogens, which statement is true? Fluorine has the highest potential and is the strongest oxidizing agent Iodine has the highest potential and is the strongest oxidizing agent Fluorine has the lowest potential and is the strongest reducing agent Chlorine has a higher potential than Fluorine The standard reduction potential for Li +/Li , Zn 2+ /Zn , H +/H 2 and Ag +/Ag are -3.05, -0.76, 0.00 and +0.80V respectively. Which is the strongest reducing agent? Li Zn H 2 Ag When KMnO 4 acts as an oxidizing agent in acidic medium, the oxidation state of Mn changes from +7 to: +2 +4 +6 +3 The quantity of electricity required to reduce 1 mol of MnO 4 - to Mn 2+ is: 5F 1F 3F 2F The number of moles of electrons required to reduce 1 mole of Cr 2O 7 2- to Cr 3+ in acidic medium is: 6 3 2 12 In which of the following molecules is the oxidation state of the central atom zero? Ni(CO) 4 CO 2 CH 4 H 2O What is the average oxidation state of manganese in Mn 3O 4 ? +8/3 +2 +3 +4 For the redox titration of KMnO 4 against oxalic acid, which of the following is used as an indicator? KMnO 4 itself Phenolphthalein Methyl orange Starch In the reaction H 2S + Cl 2 2HCl + S , which substance is oxidized? H 2S Cl 2 HCl S According to the electrochemical series, which of the following is the strongest oxidizing agent? F 2 Cl 2 O 2 I 2 The oxidation states of oxygen in F 2O and H 2O 2 are, respectively: +2 and -1 -2 and -1 -2 and +1 +2 and +1 Which of the following is a disproportionation reaction? 2H 2O 2(aq) 2H 2O(l) + O 2(g) CH 4(g) + 2O 2(g) CO 2(g) + 2H 2O(l) 2KClO 3(s) 2KCl(s) + 3O 2(g) CuO(s) + H 2(g) Cu(s) + H 2O(l) The oxidation state of Chromium in K 2Cr 2O 7 is: +6 +7 +3 +4 In the reaction O 3 + 2NO N 2O 5 + O 2 (hypothetical representation of steps), if we consider the redox change NO N 2O 5 , the oxidation state of Nitrogen changes from: +2 to +5 +2 to +3 +1 to +5 0 to +5 If the standard electrode potential ( E ) of a metal is highly negative, it means that: The metal is a strong reducing agent The metal ion is easily reduced The metal is a strong oxidizing agent The metal is chemically inert The average oxidation state of Carbon in acetic acid ( CH 3COOH ) is: 0 +2 -2 +4 The standard reduction potential for F 2/F - is the highest ( +2.87 V ) in the electrochemical series. This implies that: F 2 is the strongest oxidizing agent F - is the strongest oxidizing agent F 2 is easily oxidized F - is the strongest reducing agent What is the oxidation state of Oxygen in Potassium superoxide ( KO 2 )? -1/2 -1 -2 0 Standard electrode potential of three metals X, Y, Z are -1.2V, +0.5V and -3.0V respectively. The reducing power of these metals will be: Z > X > Y X > Y > Z Y > Z > X Y > X > Z The oxidation number of Platinum in [Pt(NH 3) 2Cl 2] is: +2 0 +4 -2 What is the oxidation state of oxygen in OF 2 ? +2 -2 -1 0 The reaction Cl 2(g) + 2OH -(aq) ClO -(aq) + Cl -(aq) + H 2O(l) represents: Disproportionation reaction Comproportionation reaction Displacement reaction Decomposition reaction What is the oxidation state of iodine in H 5IO 6 (periodic acid)? +7 +5 +1 +3 The oxidation number of Nickel in [Ni(CO) 4] is: 0 +2 +4 -2 The oxidation number of oxygen in H 2O 2 is: -1 -2 0 +1 The oxidation state of phosphorus in hypophosphorous acid ( H 3PO 2 ) is: +1 +3 +5 -1 The equivalent weight of K 2Cr 2O 7 in the titration against Fe 2+ in acidic medium is given by (where M is the molar mass): M/6 M/3 M/2 M/1 Consider the following standard reduction potentials: E Fe 2+ /Fe = -0.44 V and E Sn 2+ /Sn = -0.14 V . If a piece of iron is placed in a solution of Sn 2+ ions: Fe will reduce Sn 2+ to Sn Sn will reduce Fe 2+ to Fe No reaction will occur Iron will be plated with Tin and Tin will be oxidized The reaction 2Cu +(aq) Cu 2+ (aq) + Cu(s) is an example of: Disproportionation Comproportionation Neutralization Displacement In the reaction 3Br 2 + 6OH - 5Br - + BrO 3 - + 3H 2O , bromine is: Both oxidized and reduced Only oxidized Only reduced Neither oxidized nor reduced The oxidation state of Phosphorus in orthophosphoric acid ( H 3PO 4 ) and pyrophosphoric acid ( H 4P 2O 7 ) are, respectively: +5 and +5 +3 and +5 +5 and +3 +5 and +4 The standard reduction potentials for A, B and C are +0.68 V, -2.54 V and -0.50 V respectively. The order of their reducing power is: B > C > A A > C > B C > B > A B > A > C What is the average oxidation state of iron in magnetite ( Fe 3O 4 )? +8/3 +2 +3 +4 In chromyl chloride ( CrO 2Cl 2 ), the oxidation state of chromium is: +6 +4 +3 +2 The oxidation state of sulfur in pyrosulphuric acid ( H 2S 2O 7 ) is: +6 +4 +7 +5 The n-factor for KMnO 4 in a strongly alkaline medium is: 1 3 5 2 When Cu metal is reacted with concentrated HNO 3 , the gas evolved is: NO 2 NO N 2O H 2 In the complex K 4[Fe(CN) 6] , the oxidation state and coordination number of iron are, respectively: +2 and 6 +3 and 6 +2 and 4 +3 and 4 Among the following halogen acids, which one is the strongest reducing agent? HI HBr HCl HF In the titration of K 2Cr 2O 7 with FeSO 4 in acidic medium, how many moles of Fe 2+ are oxidized by one mole of K 2Cr 2O 7 ? 6 3 1 2 The oxidation state of Osmium in OsO 4 is: +8 +4 +6 +7 In the reaction 3Br 2 + 6CO 3 2- + 3H 2O 5Br - + BrO 3 - + 6HCO 3 - , the bromine is: Both oxidized and reduced Oxidized only Reduced only Neither oxidized nor reduced In the coordination compound Fe(CO) 5 , the oxidation state of the central iron atom is: 0 +2 +3 +5 For the balanced redox reaction Cr 2O 7 2- + 14H + + 6I - 2Cr 3+ + 3I 2 + 7H 2O , how many moles of electrons are transferred per mole of Cr 2O 7 2- ? 6 3 12 1 What is the oxidation state of Sulfur in sulfurous acid ( H 2SO 3 ) and sulfuric acid ( H 2SO 4 ) respectively? +4 and +6 +6 and +4 +2 and +6 +4 and +4 The oxidation state of Xenon in the compound XeF 6 is: +6 +4 +8 0 In the H 2-O 2 fuel cell, the overall cell reaction is equivalent to: The combustion of hydrogen to form water. The electrolysis of water to form H 2 and O 2 . The oxidation of H 2 to H + in acidic medium. The reduction of O 2 to OH - in basic medium. The oxidation number of Iron in Fe 2(CO) 9 is: 0 +2 +3 +1.5 In the balanced reaction BrO 3 - + 5Br - + 6H + 3Br 2 + 3H 2O , which species acts as the oxidizing agent? BrO 3 - Br - H + Br 2 What is the oxidation state of nitrogen in the nitride ion ( N 3- ) and the azide ion ( N 3 - ) respectively? -3 and -1/3 -3 and -3 -1 and -3 +3 and -1/3 When 0.1 mol MnO 4 2- is oxidized to MnO 4 - , the quantity of electricity required is: 9650 C 96500 C 19300 C 48250 C According to the IUPAC convention, if the potential of a half-cell is measured against the Standard Hydrogen Electrode (SHE) and the SHE acts as the anode, the measured potential is called the: Standard reduction potential Standard oxidation potential Standard cell EMF Overpotential In the reaction between KMnO 4 and KI in a neutral or faintly alkaline medium, MnO 4 - is reduced to: MnO 2 Mn 2+ MnO 4 2- Mn 2O 3 Oxidation number of P in PO4 3- , of S in SO4 2- and that of Cr in Cr2O7 2- are respectively : +3,+6 and +6 +5,+6 and +6 +3,+6 and +5 +5,+3 and +6 Depressant used in the concentration of an ore containing ZnS and PbS is Na2SO4 Na2CO3 NaCl NaCN On which of the following properties does the coagulating power of an ion depend? Both magnitude and sign of the charge on the ion Size of the ion alone The magnitude of the charge on the ion alone The sign of charge on the ion alone What is the change in oxidation number of carbon in the following reaction? CH4(g) + 4Cl2(g) -> CCl4(l) + 4HCl(g) 0 to + 4 − 4 to + 4 0 to − 4 + 4 to + 4 Which of the following reactions is the metal displacement reaction? Choose the right option. Cr2O3 + 2Al ->[ ] Al2O3 + 2Cr Fe + 2HCl -> FeCl2 + H2 2Pb(NO3)2 -> 2PbO + 4NO2 + O2 2KClO3 ->[ ] 2KCl + 3O2 The oxidation state of nitrogen in NO 2 + (nitronium ion) is: +5 +4 +3 +6 Which reaction is NOT a redox reaction? Zn + CuSO4 -> ZnSO4 + Cu 2KClO3 + I2 -> 2KIO3 + Cl2 H2 + Cl2 -> 2HCl BaCl2 + Na2SO4 -> BaSO4 + 2NaCl Consider the following compounds : K O2 , H2 O 2 and H2 S O4 The oxidation state of the underlined elements in them are, respectively, +4, -4, and +6 +1, -1, and +6 +2, -2, and +6 +1, -2, and +4 In which of the following compounds, nitrogen exhibits the highest oxidation state? N 3H NH 2OH N 2H 4 NH 3 A solution contains Fe 2+ , Fe 3+ and I - ions. This solution was treated with iodine at 35 C . E for Fe 3+ /Fe 2+ is +0.77V and E for I 2/2I - is +0.536V . The favourable redox reaction is: I - will be oxidized to I 2 by Fe 3+ (I 2) will be reduced to I - by Fe 2+ There will be no redox reaction Fe 2+ will be oxidized to Fe 3+ by I 2 The oxidation state of sulfur in Na 2S 4O 6 is: +2.5 (average) +2 +4 +6 Corrosion of iron is essentially an electrochemical phenomenon where the iron at the anode is oxidized to: Fe 2+ Fe 3+ Fe(OH) 3 FeO The oxidation state of chromium in the blue-colored compound CrO 5 (chromium pentoxide) is: +6 +10 +5 +4 What are the two different oxidation states of nitrogen in the compound ammonium nitrate ( NH 4NO 3 )? -3 and +5 +3 and -5 -3 and +3 +5 and +5 When MnO 4 2- (manganate ion) is placed in an acidic solution, it undergoes disproportionation. The products formed are: MnO 4 - and MnO 2 Mn 2+ and MnO 2 MnO 4 - and Mn 2+ MnO 2 and Mn(OH) 2 The coefficient of H + in the balanced redox equation for MnO 4 - + C 2O 4 2- + H + Mn 2+ + CO 2 + H 2O is: 16 8 10 5 Which of the following molecules has an atom with a fractional oxidation state? Na 2S 4O 6 K 2Cr 2O 7 H 2SO 4 KMnO 4 Which of the following is NOT a redox reaction? BaCl 2 + H 2SO 4 BaSO 4 + 2HCl 2K + F 2 2KF CuO + H 2 Cu + H 2O 2NaOH + Cl 2 NaCl + NaClO + H 2O In the bleaching powder CaOCl 2 , the oxidation states of the two chlorine atoms are: +1 and -1 0 and 0 -1 and -1 +1 and +1 What is the oxidation state of Phosphorus in Ba(H 2PO 2) 2 ? +1 +3 -3 +5 The number of electrons involved in the reduction of one mole of IO 3 - to I 2 is: 5 10 6 2 The oxidation state of Nitrogen in Hydrazoic acid ( HN 3 ) is: -1/3 -3 +3 +1/3 In the balanced chemical equation for the reaction IO 3 - + a I - + b H + c I 2 + d H 2O , the values of a, b, c and d are: 5, 6, 3, 3 3, 4, 2, 2 5, 3, 3, 3 2, 6, 3, 3 What is the oxidation number of sulfur in peroxodisulphuric acid ( H 2S 2O 8 )? +6 +7 +8 +4 When MnO 4 - reacts with I - in a weakly basic or neutral medium, the oxidation state of Manganese changes from +7 to: +4 +2 +6 +3 In the reaction P 4 + 3NaOH + 3H 2O PH 3 + 3NaH 2PO 2 , phosphorus is: Both oxidized and reduced Only oxidized Only reduced Neither oxidized nor reduced In the reaction K 2Cr 2O 7 + 14HCl 2KCl + 2CrCl 3 + 3Cl 2 + 7H 2O , the equivalent weight of K 2Cr 2O 7 is: M/6 M/3 M/2 M/1 The oxidation state of phosphorus in magnesium pyrophosphate ( Mg 2P 2O 7 ) is: +5 +3 +4 +7 In the reaction Br 3O 8 + 16H + + 10e - 3Br 2+ + 8H 2O , what is the average oxidation state of bromine in tribromine octoxide ( Br 3O 8 )? +16/3 +6 +4 +14/3 The oxidation number of Nitrogen in hydroxylamine ( NH 2OH ) is: -1 -2 -3 +1 What is the oxidation number of oxygen in dioxygen difluoride ( O 2F 2 )? +1 +2 -1 -2 The standard electrode potential for the half-cell Cl 2(g) + 2e - 2Cl -(aq) is +1.36 V . The potential for the half-cell 1/2 Cl 2(g) + e - Cl -(aq) will be: +1.36 V +0.68 V +2.72 V -1.36 V In the reaction XeF 4 + 2H 2O Xe + 1/2 O 2 + 4HF + XeO 3 (simplified disproportionation), what is the change in the oxidation state of Xenon? +4 0 and +4 +6 +4 0 only +2 0 and +2 +4 +6 0 and +6 +8 In the titration of K 2Cr 2O 7 with FeSO 4 , the use of K 3[Fe(CN) 6] as an external indicator produces a blue color when: Fe 2+ ions are still present in the solution All Fe 2+ ions have been oxidized to Fe 3+ The solution becomes neutral Cr 3+ ions are formed The amount of electricity required to convert 1 mole of manganate ( MnO 4 2- ) to permanganate ( MnO 4 - ) is: 1 F 2 F 5 F 0.5 F What is the standard reduction potential of the O 2/H 2O half-cell at pH = 0 at 298 K ? +1.23 V +0.82 V 0.00 V +2.87 V The disproportionation of the hypochlorite ion ( ClO - ) into chlorate ( ClO 3 - ) and chloride ( Cl - ) ions is: 3ClO - ClO 3 - + 2Cl - 2ClO - ClO 2 - + Cl - ClO - + H 2O ClO 2 - + H 2 4ClO - ClO 4 - + 3Cl - The oxidation state of Boron in Lithium Borohydride ( LiBH 4 ) is: -3 +3 +1 0