d- and f-Block Elements

The spin-only magnetic moment value of the ion among Ti2+, V2+, Co3+ and Cr2+, that acts as strong oxidising agent in aqueous solution is BM (Near integer). (Given atomic numbers : Ti : 22, V : 23, Cr : 24, Co : 27)

The number of ions from the following that have the ability to liberate hydrogen from a dilute acid is . Ti2+, Cr2+ and V2+

1. 1
2. 2
3. 3
4. 0

The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products A and B along with the evolution of CO2. The sum of spin-only magnetic moment values of A and B is B.M. (Nearest integer) [Given atomic number : C : 6, Na : 11, O : 8, Fe : 26, Cr : 24]

The element which shows only one oxidation state other than its elemental form is :

1. Nickel
2. Titanium
3. Cobalt
4. Scandium

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