ExamGOAL
Books
56
Subjective

Match the solutions given in Column I and the colours given in Column II.

Column I
(Aqueous solution of salt)
Column II
(Colour)
A. $\mathrm{FeSO_4 . 7H_2O}$ 1. Green
B. $\mathrm{NiCl_2 . 4H_2O}$ 2. Light pink
C. $\mathrm{MnCl_2 4H_2O}$ 3. Blue
D. $\mathrm{CoCl_2 . 6H_2O}$ 4. Pale green
E. $\mathrm{Cu_2Cl_2}$ 5. Pink
6. Colourless

Explanation

A. $\rightarrow$ (4) B. $\rightarrow$ (1) C. $\rightarrow(2)$ D. $\rightarrow$ (5) E. $\rightarrow$ (6)

(Aqueous solution of salt) (Colour)
A. $\mathrm{FeSO_4 . 7H_2O}$ 1. Pale green
B. $\mathrm{NiCl_2 . 4H_2O}$ 2. Green
C. $\mathrm{MnCl_2 4H_2O}$ 3. Light pink
D. $\mathrm{CoCl_2 . 6H_2O}$ 4. Pink
E. $\mathrm{Cu_2Cl_2}$ 5. Colourless

57
Subjective

Match the property given in Column I with the element given in Column II.

Column I
(Property)
Column II
(Element)
A. Lanthanoid which shows +4 oxidation state 1. Pm
B. Lanthanoid which can show +2 oxidation state 2. Ce
C. Radioactive lanthanoid 3. Lu
D. Lanthanoid which has $4f^7$ electronic configuration in +3 oxidation state 4. Eu
E. Lanthanoid which has $4f^{14}$ electronic configuration in +3 oxidation state 5. Gd
6. Dy

Explanation

A. $\rightarrow(2)$ B. $\rightarrow$ (4) C. $\rightarrow$ (1) D. $\rightarrow(5)$ E. $\rightarrow$ (3)

A. Lanthanoid which shows +4 oxidation state is cerium.

${ }_{58} \mathrm{Ce}=[\mathrm{Xe}] 4 f^2 5 d^0 6 \mathrm{~s}^2 ;$ Oxidation state $=+3,+4$

B. Lanthanoid which can show +2 oxidation state is europium.

${ }_{63} \mathrm{Eu}=[\mathrm{Xe}] 4 f^7 5 d^0 6 \mathrm{~s}^2$; Oxidation state $=+2,+3$

C. Radioactive lanthanoid is promethium. It is the only synthetic (man-made) radioactive lanthanoid.

D. Lanthnoid which has $4 f^7$ electronic configuration in +3 oxidation state is gadolinium.

${ }_{64} \mathrm{Gd}=[\mathrm{Xe}] 4 f^7 5 d^1 6 s^2$; Oxidation state $=+3$

E. Lanthanoid which has $4 f^{14}$ electronic configuration in +3 oxidation state is lutetium

${ }_{71} \mathrm{Lu}=[\mathrm{Xe}] 4 f^{14} 5 d^1 6 s^2 ;$ Oxidation state $=+3$

58
Subjective

Match the properties given in Column I with the metals given in Column II.

Column I
(Property)
Column II
(Metal)
A. Element with highest second ionisation enthalpy 1. Co
B. Element with highest third ionisation enthalpy 2. Cr
C. M in M(CO)$_6$ is 3. Cu
D. Element with highest heat of atomisation 4. Zn
5. Ni

Explanation

A. $\rightarrow(3)$ B. $\rightarrow$ (4) C. $\rightarrow(2)$ D. $\rightarrow$ (1)

A. $\mathrm{Cu}^{+}=3 d^{10}$ which is very stable configuration due to full-filled orbitals. Hence, removal of second electron requires very high energy.

B. $\mathrm{Zn}^{2+}=3 d^{10}$ which is very stable configuration. Hence, removal of third electron requires very high energy.

C. Metal carbonyl with formula $\mathrm{M}(\mathrm{CO})_6$ is $\mathrm{Cr}(\mathrm{CO})_6$.

D. Nickel is the element with highest heat of atomisation.

59
MCQ (Single Correct Answer)

Assertion $(\mathrm{A}) \mathrm{Cu}^{2+}$ iodide is not known.

Reason $(\mathrm{R}) \mathrm{Cu}^{2+}$ oxidises $\mathrm{I}^{-}$to iodine.

A
Both assertion and reason are true, and reason is the correct explanation of the assertion.
B
Both assertion and reason are true but reason is not the correct explanation of assertion.
C
Assertion is not true but reason is true.
D
Both assertion and reason are false.
60
MCQ (Single Correct Answer)

Assertion (A) Separation of Zr and Hf is difficult.

Reason (R) Because Zr and Hf lie in the same group of the Periodic Table.

A
Both assertion and reason are true, and reason is the correct explanation of the assertion.
B
Both assertion and reason are true but reason is not the correct explanation of assertion.
C
Assertion is not true but reason is true.
D
Both assertion and reason are false.