Redox Reactions

The correct decreasing order of oxidation state of the underlined atom in each molecule is

1. P4O6 > Cl2O7 > AlH3
2. P4O10 > SO3 > H2 O
3. N2O5 > Al2O3 > H2 S
4. PbO2 > N2O3 > SO3

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