Redox Reactions

Consider the following compounds : KO2, H2 O2 and H2 SO4 The oxidation state of the underlined elements in them are, respectively,

1. +1, -2, and +4
2. +4, -4, and +6
3. +1, -1, and +6
4. +2, -2, and +6

Which reaction is NOT a redox reaction?

1. Zn + CuSO4 ZnSO4 + Cu
2. 2KClO3 + I2 2KIO3 + Cl2
3. H2 + Cl2 2HCl
4. BaCl2 + Na2SO4 BaSO4 + 2NaCl

On balancing the given redox reaction, a Cr2O72-(aq) + b SO32-(aq) + cH+(aq) 2a Cr3+(aq) + b SO42-(aq) + c2H2O( ) the coefficients a, b and c are found to be, respectively -

1. 3, 8, 1
2. 1, 8, 3
3. 8, 1, 3
4. 1, 3, 8

Which of the following reactions is a decomposition redox reaction?

1. P4(s) + 3OH-(aq) + 3H2O(l) PH3(g) + 3H2PO2-(aq)
2. 2Pb(NO3)2(s) 2PbO(s) + 4NO2(g) + O2(g)
3. N2(g) + O2(g) 2NO(g)
4. Cl2(g) + 2OH-(aq) ClO-(aq) + Cl-(aq) + H2O(l)

Which of the following reactions is the metal displacement reaction? Choose the right option.

1. 2Pb(NO3)2 2PbO + 4NO2 + O2
2. 2KClO3 2KCl + 3O2
3. Cr2O3 + 2Al Al2O3 + 2Cr
4. Fe + 2HCl FeCl2 + H2

What is the change in oxidation number of carbon in the following reaction? CH4(g) + 4Cl2(g) CCl4(l) + 4HCl(g)

1. 0 to +4
2. -4 to +4
3. 0 to -4
4. +4 to +4

Which of the following reactions are disproportionation reaction? Select the correct option from the following :

1. A, C and D
2. A and B only
3. A and D only
4. A, B and C

Consider the change in oxidation state of bromine corresponding to different emf values as shown in the given diagram : BrO4- 1.82 V BrO3- 1.5 V HBrO 1.595 V Br2 1.0652 V Br- Then the species undergoing disproportionation is :

1. BrO4-
2. BrO3-
3. Br2
4. HBrO

The correct order of N-compounds in its decreasing order of oxidation states is

1. HNO3, NO, N2, NH4Cl
2. HNO3, NO, NH4Cl, N2
3. HNO3, NH4Cl, NO, N2
4. NH4Cl, N2, NO, HNO3

For the redox reaction, MnO4- + C2O42- + H+ Mn2+ + CO2 + H2O The correct coefficients of the reactants for the balanced equation are

1. array|c|c|c| MnO4- & C2O42- & H+ \ 16 & 5 & 2 \ array
2. array|c|c|c| MnO4- & C2O42- & H+ \ 2 & 5 & 16 \ array
3. array|c|c|c| MnO4- & C2O42- & H+ \ 2 & 16 & 5 \ array
4. array|c|c|c| MnO4- & C2O42- & H+ \ 5 & 16 & 2 \ array