Zr (Z=40) and Hf (Z=72) have similar atomic and ionic radii because of: 

1. lanthanoid contraction

2. having similar chemical properties

3. belonging to same group

4. diagonal relationship

The incorrect statement among the following is : 

1. Lanthanoids are good conductors of heat and electricity.

2. Actinoids are highly reactive metals, especially when finely divided.

3. Actinoid contraction is greater for element to element than Lanthanoid contraction.

4. Most of the trivalent Lanthanoid ions are colorless in the solid-state.

Match List-I with List-II

Choose the correct answer from the options given below.

1. (a)-(i), (b)-(iii), (c)-(iv), (d)-(ii)

2. (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)

3. (a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)

4. (a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)

The calculated spin only magnetic moment of Cr²⁺ ion is :

1. 4.90 BM

2. 5.92 BM

3. 2.84 BM

4. 3.87 BM

Identify the incorrect statement.

1.  The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes. 

2.  Interstitial compounds are those that are formed when small atoms like H, C or N are trapped inside the crystal lattices of metals.

3.  The oxidation states of chromium in $Cr{O}_4^{2-}$ and $C{r}_2{O}_7^{2-}$ are not the same.

4.  $C{r}^{2+}\left(d^4\right)$ is a stronger reducing agent than $F{e}^{2+}\left(d^6\right)$ in water. 

Urea reacts with water to form A which will decompose to form B. B when passed through ${\mathrm{Cu}}^{2+}$ (aq), deep blue color solution C is formed. What is the formula of C from the following? 

1. ${\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_4\right]}^{2+}$

2.  $\mathrm{Cu}{\left(\mathrm{OH}\right)}_2$

3.  ${\mathrm{CuCO}}_3.\mathrm{Cu}{\left(\mathrm{OH}\right)}_2$

4.   ${\mathrm{CuSO}}_4$

Identify the incorrect statement from the following:

(1) Zirconium and Hafnium have identical radii of 160 pm and 159 pm, respectively as a consequence of lanthanoid contraction.

(2) Lanthanoids reveal only +3 oxidation state.

(3) The lanthanoid ions other than the f⁰ type and the f¹⁴ type are all paramagnetic.

(4) The overall decrease in atomic and ionic radii from lanthanum to lutetium is called lanthanoid contraction.

Match the following aspects with the respective metal.

    Aspects                                            Metal

(a) The metal which reveals                 (i) Scandium
the maximum number of oxidation
states

(b) The metal although placed              (ii) Copper
in 3d block is not considered
as a transition element

(c) The metal which does not exhibit     (iii) Manganese
variable oxidation states

(d) The metal which in +1 oxidation       (iv) Zinc
state in aqueous solution undergoes
disproportionation

Select the correct option :
(1) (a)-(i)   (b)-(iv)  (c)-(ii)  (d)-(iii)

(2) (a)-(iii)  (b)-(iv)  (c)-(i)  (d)-(ii)

(3) (a)-(iii)  (b)-(i)   (c)-(iv)  (d)-(ii)

(4) (a)-(ii)  (b)-(iv)  (c)-(i)   (d)-(iii)

The manganate and permanganate ions are tetrahedral, due to:

1.  The $\mathrm{\pi }$-bonding which involves overlap of d-orbitals of oxygen with d-orbitals of manganese

2.  The $\mathrm{\pi }$-bonding which involves overlap of p-orbitals of oxygen with d-orbitals of manganese

3.  Absence of $\mathrm{\pi }$-bonding

4.  The $\mathrm{\pi -}$bonding which involves overlap of p-orbitals of oxygen with p-orbitals of manganese

Match the catalyst with the process:

   Catalyst                           Process 

(i) $V_2{O}_5$                          (a) The oxidation of ethylene to ethanal

(ii) TiCl₄ + Al(CH₃)₃          (b) Polymerisation of alkynes

(iii) $PdC{l}_2$                         (c) Oxidation of $S{O}_2$ in the manufacture of $H_{2}S{O}_4$

(iv) Nickel complexes         (d) Polymerisation of ethylene

Which of the following is the correct matching of Catalyst & Process?

(1) (i)-(c), (ii)-(d), (iii)-(a), (iv)-(b)

(2) (i)-(a), (ii)-(b), (iii)-(c), (iv)-(d)

(3) (i)-(a), (ii)-(n), (iii)-(b), (iv)-(d)

(4) (i)-(c), (ii)-(a), (iii)-(d), (iv)-(b)