General
✓✗Statement I: In the reaction 2NO2 + H2O → HNO3 + HNO2, nitrogen is both oxidised and reduced.
Statement II: In the reaction NH4NO2 → N2 + 2H2O, nitrogen undergoes disproportionation.
Statement II: In the reaction NH4NO2 → N2 + 2H2O, nitrogen undergoes disproportionation.
- Both Statement I and Statement II are correct
- 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
General
✓✗The oxidation number of Pb in Pb3O4 (average) is
- +4
- +3
- +8/3
- +2
General
✓✗In the electrochemical series arranged in order of decreasing standard reduction potential, the element at the bottom is
- least reactive
- always a non-metal
- the strongest reducing agent
- the strongest oxidising agent
General
✓✗In which of the following oxides does the metal have the highest oxidation number?
- Cr in CrO3
- Mn in MnO2
- Fe in Fe2O3
- V in V2O5
General
✓✗In neutral or weakly alkaline medium, MnO4− is reduced to
- Mn (7 electrons per Mn)
- MnO42− (1 electron per Mn)
- MnO2 (3 electrons per Mn)
- Mn2+ (5 electrons per Mn)
General
✓✗An element X has E°(X2+/X) = −0.25 V. Which statement is correct?
- X2+ is a stronger oxidant than Cu2+ (E° = +0.34 V)
- X can reduce Zn2+ to Zn
- X can liberate H2 from dilute HCl, and X2+ ions can be reduced by Zn (E° = −0.76 V)
- X cannot react with dilute HCl
General
✓✗According to the electronic concept, oxidation is
- loss of electrons
- loss of protons
- gain of protons
- gain of electrons
General
✓✗The oxidation number of Mn in KMnO4 is
- +7
- +4
- +5
- +6
General
✓✗Without losing its concentration, a ZnCl2 solution cannot be kept in contact with
- Au
- Al
- Ag
- Pb
General
✓✗Assertion: The reaction NaCl + AgNO3 → AgCl + NaNO3 is not a redox reaction.
Reason: No element changes its oxidation number in this reaction.
Reason: No element changes its oxidation number in this reaction.
- Both Assertion and Reason are true and Reason is the correct explanation of Assertion
- Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
- Assertion is true but Reason is false
- Both Assertion and Reason are false
General
✓✗The oxide which cannot act as a reducing agent is
- SO2
- CO2
- NO2
- ClO2
General
✓✗Statement I: Silver can displace hydrogen from dilute HCl.
Statement II: The standard reduction potential of silver is positive.
Statement II: The standard reduction potential of silver is positive.
- Both Statement I and Statement II are correct
- 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
General
✓✗In the reaction 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O, the fraction of HNO3 that acts as an oxidising agent is
- 1/4
- 3/4
- 1/2
- 1
General
✓✗Statement I: The oxidation number of Cr in K2Cr2O7 and in K2CrO4 is the same.
Statement II: The conversion of CrO42− to Cr2O72− on adding acid is a redox reaction.
Statement II: The conversion of CrO42− to Cr2O72− on adding acid is a redox reaction.
- Both Statement I and Statement II are correct
- 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
General
✓✗Which of the following processes does not involve oxidation of iron?
- Liberation of H2 from steam by iron at high temperature
- Formation of Fe(CO)5 from Fe
- Decolourisation of blue CuSO4 solution by iron
- Rusting of iron sheets