The example of disproportionation reaction among the following is:
1. 3\(MnO_{4}^{2-}\)+ 4 H+ → 2\(MnO_{4}^{-}\) + MnO2 + 2H2O
2. Na2Cr2O7 + 2 KCl → K2Cr2O7 + 2 NaCl
3. PCl5 + H2O → POCl3 + 2HCl
4. 2MnO2 + 4KOH + O2 → 2K2MnO4 + 2H2O
The well known element of lanthanoid series that exhibit +4 oxidation state, is-
1. Ac
2. Ce
3. Eu
4. Yb
The magnetic moment of a divalent ion (atomic number = 25) in aqueous solution is:
1. 4.34
2. 5.92
3. 6.12
4. 4.87
The correct sequence of decreasing oxidizing power of VO2+, MnO4– , Cr2O72– is:
1. VO2+ > MnO4– > Cr2O72–
2. MnO4– > Cr2O72– > VO2+
3. MnO4– < Cr2O72– < VO2+
4. Cr2O72– > VO2+ > MnO4–
Given below are two statements:
Assertion (A): | Cr2+ acts as a reducing agent and Mn3+ acts as an oxidising agent when both have d4 configuration. |
Reason (R): | The maximum oxidation state Cr show is +5 and Mn shows is +7. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
Which transition element does not exhibit variable oxidation states?
1. Manganese (\(Mn\))
2. Chromium(\(Cr\))
3. Scandium(\(Sc\))
4. Iron(\(Fe\))
The transition elements exhibit higher enthalpies of atomisation because-
1. | It has stronger interatomic interaction |
2. | It has stronger hydrogen bonding |
3. | It has paired electrons |
4. | It has strong vanderwaal interaction |
Scandium (Z = 21) is a transition element but zinc (Z = 30) is not because-
1. Sc has 3d0 and Zn has 3d10
2. Sc has 3d1 and Zn has 3d10
3. Sc has 3d10 and Zn has 3d1
4. None of the above