Match Column I (Catalyst) with Column II (Process), and mark the appropriate option:

	Column I - (Catalyst)		Column II - (Process)
A.	Ni in the presence of hydrogen	1.	Contact process
B.	Cu2Cl2	2.	Vegetable oil to ghee
C.	V2O5	3.	Sandmeyer reaction
D.	Finely divided iron	4.	Haber's process
		5.	Decomposition of  KClO3

 

Codes:

	A	B	C	D
1.	3	4	2	5
2.	2	3	1	4
3.	5	4	3	2
4.	4	5	3	2

The electronic configuration of gadolinium (atomic number of 64) is:

1. $\left[\mathrm{Xe}\right]4{\mathrm{f}}^{3}5{\mathrm{d}}^{5}6{\mathrm{s}}^2$

2. $\left[\mathrm{Xe}\right]4{\mathrm{f}}^{7}5{\mathrm{d}}^{2}6{\mathrm{s}}^1$

3. $\left[\mathrm{Xe}\right]4{\mathrm{f}}^{7}5{\mathrm{d}}^{1}6{\mathrm{s}}^2$

4. $\left[\mathrm{Xe}\right]4{\mathrm{f}}^{8}5{\mathrm{d}}^{6}6{\mathrm{s}}^2$

The metallic radii of some transition elements are given below. An element that has the highest density is:

1. Fe 

2. Ni

3. Co

4. Cu

Highest oxidation state of manganese in fluoride is +4 (Mn$F_4$) but the highest oxidation state in oxides is +7 (Mn₂O₇). The reason is :

Among the following, which are amphoteric oxides?

1. V₂O₅, Cr₂O₃
2. Mn₂O₇, CrO₃
3. CrO, V₂O₅
4. V₂O₅, V₂O₄

Colourless ion among the following is:

An element among the following that exhibits the maximum oxidation state is:

1. Cr

2. Mn

3. Fe

4. V

Mn²⁺ compounds are more stable than Fe²⁺ compounds towards oxidation in their +3 state because :

The oxo metal anions of the 3d series in which the metal exhibits an oxidation state equal to its group number is /are -

1. ${\mathrm{VO}}_3^{-}$

2. ${\mathrm{CrO}}_4^{2-}$

3. ${\mathrm{MnO}}_4^{-}$

4. All of the above.

What is the electronic configuration of transition elements?