d- and f-Block Elements

Consider the following reaction MnO2 + KOH + O2 A + H2O. Product 'A' in neutral or acidic medium disproportionate to give products 'B' and 'C' along with water. The sum of spin-only magnetic moment values of B and C is BM. (nearest integer) (Given atomic number of Mn is 25)

A first row transition metal in its +2 oxidation state has a spin-only magnetic moment value of 3.86 BM. The atomic number of the metal is

1. 22
2. 23
3. 26
4. 25

A first row transition metal with highest enthalpy of atomisation, upon reaction with oxygen at high temperature forms oxides of formula M2On (where n = 3, 4, 5). The 'spin-only' magnetic moment value of the amphoteric oxide from the above oxides is BM (near integer) (Given atomic number: Sc : 21, Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26, Co : 27, Ni : 28, Cu : 29, Zn : 30)

In acidic medium, K2Cr2O7 shows oxidising action as represented in the half reaction: Cr2O72- + XH+ + Ye 2A + ZH2O X, Y, Z and A are respectively :

1. 14, 7, 6 and Cr3+
2. 14, 6, 7 and Cr3+
3. 8, 4, 6 and Cr2O3
4. 8, 6, 4 and Cr2O3

The transition metal having highest 3rd ionisation enthalpy is :

1. Mn
2. Fe
3. Cr
4. V

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the most appropriate answer from the options given below :

1. (A) is true but (R) is false
2. Both (A) and (R) are true and (R) is the correct explanation of (A)
3. Both (A) and (R) are true but (R) is not the correct explanation of (A)
4. (A) is false but (R) is true

Which of the following compounds show colour due to d-d transition?

1. K2Cr2O7
2. CuSO4 5H2O
3. KMnO4
4. K2CrO4

Identify correct statements from below: Choose the correct answer from the options given below:

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

The metals that are employed in the battery industries are Choose the correct answer from the options given below:

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

Choose the correct statements from the following Choose the correct answer from the options given below :

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