Match  Column I with Column II and mark the most appropriate option:

Column I (Metal ion)	Column II (Spin magnetic moment)
A. Co3+	i. √8 B.M.
B. Cr3+	ii. √35 B.M.
C. Fe3+	iii. √15 B.M.
D. Ni2+	iv. √24 B.M.

 

	A	B	C	D
1.	iv	iii	ii	i
2.	i	ii	iii	iv
3.	iv	i	ii	iii
4.	iii	iv	i	ii

When copper is heated with conc. HNO₃ it produces:

1. Cu(NO₃) and NO

2. Cu(NO₃)₂, NO and NO₂

3. Cu(NO₃)₂ and N₂O

4. Cu(NO₃)₂ and NO₂

Gadolinium belongs to 4f series. It’s atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?

1. $\left[Xe\right]4 f^8 6d^2$

2. $\left[Xe\right]4 f^9 5s^1$

3. $\left[Xe\right]4 f^7 5d^{1}6s^2$

4. $\left[Xe\right]4 f^6 5d^{2}6s^2$

A pair among the following have nearly the same atomic radii:

(Numbers in the parenthesis are atomic numbers).

Which of the following processes does not involve the oxidation of iron?

The number of d -electrons in Fe²⁺ (atomic number  Z = 26)  is different from the number of:
1. s-electrons in Mg (Z = 12)
2. p-electrons in Cl (Z = 17)
3. d-electrons in Fe (Z = 26)
4. p-electrons in Ne (Z = 10)

The pair of compounds that can exist together is:

1. FeCl₃, SnCl₂

2. HgCl, SnCl₂

3. FeCl₂, SnCl₂

4. FeCl₃, Kl

In acidic medium, H₂O₂ changes Cr₂O₇^–2 to CrO₅ which has two (–O – O–) bonds.
The oxidation state of Cr in CrO₅ is:

1. +5

2. +3

3. +6

4. -10