Q1. For the redox reactionMnO4– + C2O42- + H+ → Mn2+ + CO2 + H2O .The correct coefficients of the reactants for the balanced reaction are:
- MnO4– = 2 C2O42- = 5 H+ = 16
- MnO4– = 16 C2O42- = 5 H+ = 2
- MnO4– = 5 C2O42- = 16 H+ = 2
- MnO4– = 2 C2O42- = 16 H+ = 5
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Q2. A substance (atom, ion or molecule) which can readily accept electrons from other substances is called
- Oxidising agent
- Reducing agent
- None of them
- both a and b
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Q3. The oxidation number of Mg in Mg+2 is
- +2
- +1
- -2
- -1
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Q4. 2 K4 [Fe (CN)6](aq) + H2O2 (aq) → 2 K3 [Fe (CN)6](aq) + 2KOH(aq) is an example of
- Oxidation
- Reduction
- Replacement
- Addition
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Q5. The balanced half reaction is:
- MnO4-1(aq) + 2H2O(l) + 3e– → MnO2(s) + 4OH–(aq)
- MnO4-1(aq) + 2H2O(l) → MnO2(s) + 4OH–(aq)
- MnO4-1(aq) + 2H2O(l) + 3e– → MnO2(s) + OH–(aq)
- 4MnO4-1(aq) + 2H2O(l) → MnO2(s) + 4OH–(aq)
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Q6. The process in which the strength of an unknown solution is calculated using a known standard solution is known as
- titration
- oxidation
- reduction
- none of these
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Q7. In Ni(CO)4 the oxidation number of Ni is
- 4
- 2
- 8
- 0
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Q8. In 2Na(S) + Cl2 → 2 NaCl (S) ; The oxidising agent is
- Sodium
- Chlorine
- Sodium chloride
- None of these
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Q9. Given the standard reduction potentials:Zn2+/Zn = – 0.74 V, Cl2/Cl– = 1.36 V, H+/1/2H2 = 0 V and Fe3+/Fe2+ = 0.77 V. The order of increasing strength as reducing agent is
- Zn, H2, Fe2+, Cl–
- H2, Zn, Fe2+, Cl–
- Cl–, Fe2+,Zn, H2
- Cl–, Fe2+, H2, Zn
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Q10. Find out EMF of cell, Zn|Zn2+(1M) || Cu2+(1M)|CuEo for Zn2+/Zn = -0.76 V, Eo for Cu2+/Cu = +0.34 V
- +1.10 V
- -1.10 V
- -0.76 V
- -0.42 V
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Q11. Which of the following is NOT true about the oxidation state of oxygen?
- It shows oxidation state +3.
- It shows oxidation state +2.
- It shows oxidation state -1/2.
- It shows oxidation states -1.
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Q12. When Zinc rod is dipped in copper nitrate solution, the blue colour of copper nitrate solution starts fading. The substance that undergoes oxidation is
- Zn(s)
- Zn2+
- Cu(s)
- Cu2+
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Q13. The standard electrode potentials, K+/K= -2.93V, Ag+/Ag = 0.80V, the electrode which is negatively charged is
- Ag+/Ag
- K+/K
- Any of the two
- None of them
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Q14. The oxidation and reduction half reactions of the reaction2Al(s) + 3Cu2+(aq) → 2Al3+(aq) + 3Cu(s) are
- Oxidation: 2Al(s) → Al3+(aq) + 3e– ] x 2 Reduction: Cu2+ + 2e– → Cu(s) ] x 3
- Oxidation: Al(s) → Al3+ + 3e– ] x 2 Reduction: Cu2+ + 2e– → Cu(s) ] x 3
- Oxidation: Al(s) → Al3+(aq) + 3e– ] x 2 Reduction: 2Cu2+(aq) + 2e– → Cu(s) ] x 3
- Oxidation: Al(s) → Al3+(aq) + 3e– ] x 2 Reduction: Cu2+(aq) + 2e– → Cu(s) ] x 2
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Q15. To balance the oxygen atom in the given reaction in acidic medium,Cr2O72-(aq) → Cr3+(aq) we will,
- Add O on left side
- Add water (H2O) on left side
- Add water (H2O) on right side
- Add O on right side
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Q16. In which of the following method, two half equations are balanced separately and then added together to give balanced equation?
- Half reaction method
- Reducing agent method
- Oxidizing agent method
- Reluctant method
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Q17. A substance (atom, ion or molecule) which can readily loose electrons to other substances is called
- Oxidising agent
- Reducing agent
- None of them
- both a and b
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Q18. To balance the charge in the oxidation half reaction Fe2+(aq) → Fe3+(aq)
- Add an electron on reactant side
- Add an electron on product side
- Add two electrons on reactant side
- Add two electrons on product side
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Q19. A standard hydrogen electrode has zero electrode potential because
- Hydrogen is easiest to oxidize.
- The electrode potential is assumed to be zero.
- Hydrogen atom has only one electron.
- Hydrogen is the lightest element.
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Q20. Balanced ionic equation for the reaction of Potassium Dichromate (VI) K2Cr2O7 with Sodium Sulphite Na2SO3 in acid solution to give Chromium (III) ion and sulphate ion is
- Cr2O7-2(aq) + 3SO32-(aq) + 8H+(aq) → 2Cr3+(aq) + 3SO42-(aq) + 4H2O(liq)
- Cr2O7-2(aq) + 2SO32-(aq) + 8H+(aq) → 2Cr3+(aq) + 3SO42-(aq) + 4H2O(liq)
- Cr2O7-2(aq) + 3SO32-(aq) + 5H+(aq) → 2Cr3+(aq) + 3SO42-(aq) + 4H2O(liq)
- Cr2O7-2(aq) + 3SO32-(aq) + 8H+(aq) → 2Cr3+(aq) + 5SO42-(aq) + 4H2O(liq)
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Q21. In the following reaction3Br2 + 6CO32- + 3H2O → 5Br – + BrO3– + 6HCO3–
- Bromine is oxidized, carbonate is reduced
- Bromine is reduced, carbonate is oxidized
- Bromine is neither reduced nor oxidized
- Bromine is reduced as well as oxidized
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Q22. The oxidation number of Fe in K4Fe(CN)6 is
- +6
- +4
- +3
- +2
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Q23. Nitrous Acid acts as a:
- Reducing agent
- Oxidising agent
- Oxidising as well as reducing agent
- None of the above
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Q24. Those reactions in which oxidation and reduction takes place simultaneously are known as
- Redox reaction
- Addition reaction
- Chemical reaction
- None of the above
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Q25. In the reaction H2S(g) + Cl2(g) → 2HCl(g) + S(s), H2S is
- Oxidised
- Reduced
- None of them
- both a and b
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Q26. The oxidation number of Ca in Ca+2 is
- +2
- -2
- +1
- -1
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Q27. For the reaction Fe2+(aq) + Cr2O72-(aq) → Fe3+(aq) + Cr3+(aq) , the reduction half reaction is,
- Cr2O72- (aq) → Cr3+ (aq)
- Fe2+ (aq) → Fe3+ (aq)
- Fe2+ (aq) + Cr2O72- (aq) → Fe3+ (aq) + Cr3+ (aq)
- None of these
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Q28. Which one of the following is reducing agent?
- Ozone
- Chlorine
- FeCl3
- Na2S2O3
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Q29. By what unit the oxidation number changes for underline elements in the following reaction-Zn + HNO3 → NH4NO3 + Zn (NO3)2 + H2O
- 4 units
- 2 units
- 6 units
- 8 units
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Q30. Pick the odd one out
- Combination redox reaction
- Displacement redox reaction
- Catalysis redox reaction
- Decomposition redox reaction
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Q31. According to classical idea of redox reactions the given example is of2 Mg(s) + O2 (g) → 2 MgO(s)
- Oxidation
- Reduction
- Redox reaction
- All the above
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Q32. The conversion of K2Cr2O7 into Cr2 (SO4)3 is a process of
- Oxidation
- Reduction
- Decomposition
- Substitution
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Q33. How many electrons are transferred during following change?2I–(aq) → I2(s)
- 4 electrons
- 0 electrons
- 2 electrons
- 1 electron
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Q34. In an electrochemical cell represented as,Zn | Zn2+(c1) || Cu2+(c2) | Cuso in this cell,
- Zn is oxidized
- Zn is reduced
- Cu is oxidized
- Cu is reduced
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Q35. The oxidation number of an element in its free state is always
- -1
- 1
- 0
- None of these
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Q36. The oxidation half reaction for following reaction isFe2+(aq) + Cr2O72-(aq) → Fe3+ (aq) + Cr3+(aq)
- Fe2+ (aq) → Fe3+(aq)
- Cr2O72-(aq) → Cr3+(aq)
- Fe3+(aq) → Fe2+ (aq)
- Cr3+(aq) → Cr2O72-(aq)
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Q37. The reaction H2S + H2O2 → SO2 + 2H2O manifests
- Oxidizing action of H2O2
- Reducing nature of H2O2
- Acidic nature of H2O2
- Alkaline nature of H2O2
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Q38. A cell is prepared by dipping a chromium rod in 1M Cr2(SO4)3 solution and an iron rod in 1M FeSO4 solution. The standard reduction potentials of Chromium and Iron electrodes are -0.75 V and -0.45 V respectively. What will be the standard EMF of the cell?
- – 0.30 V
- +0.30 V
- +0.47 V
- -0.47 V
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Q39. We can balance the following ionic equation by adding 6Fe2+(aq) + Cr2O72-(aq) → 6 Fe3+(aq) +2Cr 3+(aq)
- 7 H2O on RHS and 14 H+ on LHS
- 7 H2O on LHS and 14 H+ on RHS
- 3H2O on RHS and 6 H+ on LHS
- 3H2O on LHS and 6 H+ on RHS
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Q40. Which of the following is disproportionation reaction?
- 4 KClO3 → 3KClO4 + KCl
- C(s) + O2 (g) → CO2(g)
- CaCO3 (s) → CaO(s) + CO2(g)
- CuSO4(aq) + Zn (s) → Cu(s) + ZnSO4 (aq)
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