- 1(current)
Q. No.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
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
The transition element that does not exhibit variable oxidation states is-
1. Mn
2. Cr
3. Sc
4. Fe
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. |
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–
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 example of disproportation 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
- 1(current)
Q. No.
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