Which one of the following statements is not correct

1. Nickel forms Ni(CO)₄

2. All the transition metals form mono-metallic carbonyls

3. Carbonyl are formed by transition metals

4. Transition metals form complexes

Match the underlined atom in Column A with oxidation number in Column B.

                    A                                                          B

(a)  [Fe(CN)₅$\stackrel{\oplus }{N}$O]^2-                                                0(I)

(b)  [Ag(CN)₂]^-                                                      3(II)

(c)  [Cr(en)₃]³⁺                                                      1(III)

(d)  Ni(CO)₄                                                          2(IV)

              a         b        c       d

(A)         I         II       III      IV

(B)        II        III       IV       I

(C)       IV        III       II        I

(D)       II        III        I        IV

Assertion : Cuprous ion $\left({\mathrm{Cu}}^{+}\right)$ is colourless whereas cupric ion $\left({\mathrm{Cu}}^{2+}\right)$ produces blue colour in solution.

Reason : Cuprous ion $\left({\mathrm{Cu}}^{+}\right)$ has unpaired electrons while cupric ion $\left({\mathrm{Cu}}^{2+}\right)$ does not.

The radius of La³⁺ (atomic number of La=57) is 1.06 $\stackrel{o}{A}$. Which one of the following given values will be closest to the radius of Lu³⁺ (atomic number of Lu =71)

(1) 1.60 $\stackrel{o}{A}$

(2) 1.40 $\stackrel{o}{A}$

(3)1.96 $\stackrel{o}{A}$

(4)0.85 $\stackrel{o}{A}$

Assertion : The number of unpaired electrons in the following gaseous ions:

                   ${\mathrm{Mn}}^{3+},<mspace\; width="1em"></mspace>{\mathrm{Cr}}^{3+},<mspace\; width="1em"></mspace>{\mathrm{V}}^{3+}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{Ti}}^{3+}<mspace\; width="1em"></mspace>$are 4, 3, 2 and 1 respectively

Reason : ${\mathrm{Cr}}^{3+}$ is stable in aqueous solution.

Which of the following pairs of compounds are more stable

(A) $K_2\left[NiC{l}_6\right],\left[Pt\right(CN{)}_4{]}^{2-}$

(B) NiCl₄, PtCl₄

(C) $\left[Ni\right(CN{)}_4{]}^{2-},<mspace\; width="1em"></mspace>K_2\left[Pt\right(C{l}_6\left)\right]$

(D) PtCl₂, NiCl₂

Assertion : Ammonical silver nitrate converts glucose to gluconic acid and metallic silver is precipitated.

Reason : Glucose acts as a weak reducing agent.

Which of the following products are formed when potassium bromide reacts with potassium permanganate in alkaline pH?

1. ${{\mathrm{BrO}}_3}^{‐},<mspace\; width="1em"></mspace>{\mathrm{MnO}}_2$                                     

2. ${{\mathrm{BrO}}_4}^{‐},<mspace\; width="1em"></mspace>{\mathrm{Mn}}^{2+}$

3. ${\mathrm{Br}}_2,<mspace\; width="1em"></mspace>{\mathrm{MnO}}_2$                                         

4. ${\mathrm{Br}}_2{\mathrm{O}}^{‐},<mspace\; width="1em"></mspace>{{\mathrm{MnO}}_4}^{2‐}$

Assertion: To a solution of potassium chromate if a strong acid is added it changes its colour from yellow to orange.

Reason : The colour change is due to the oxidation of potassium chromate.