Which of the following is true for the species $3{\mathrm{d}}^4$ configuration ?

(1) ${\mathrm{Cr}}^{2+}$ is reducing in nature                               

(2) ${\mathrm{Mn}}^{3+}$ is oxidising in nature.

(3) Both (A) and (B)                                             

(4) None of these

In which compound does vanadium have an oxidation number of +4?

(A) ${\mathrm{NH}}_4{\mathrm{VO}}_2$                                 

(B) ${\mathrm{K}}_4\left[\mathrm{V}{\left(\mathrm{CN}\right)}_6\right]$

(C) ${\mathrm{VSO}}_4$                                     

(D) ${\mathrm{VOSO}}_4$

Arrange the following species in the increasing order of their magnetic properties.

${\mathrm{VCl}}_3$    ${\mathrm{VOSO}}_4$    ${\mathrm{Na}}_3{\mathrm{VO}}_4$       $\left[\mathrm{V}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\mathrm{SO}}_4.{\mathrm{H}}_2\mathrm{O}$

  I              II                  III                      IV

(1) III<II<I<IV                                         

(2) III<IV<II<I

(3) II<III<I<IV                                         

(4) IV<I<II<III

Which of the following increasing order of oxidising power is correct for the following species?

           ${{\mathrm{VO}}_2}^{+}, {{\mathrm{MnO}}_4}^{-}, {\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-}$

(A) ${{\mathrm{VO}}_2}^{+}<{\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-}<{{\mathrm{MnO}}_4}^{-}$                           

(B) ${{\mathrm{VO}}_2}^{+}<{{\mathrm{MnO}}_4}^{-}<{\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-}$

(C) ${\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-}<{{\mathrm{VO}}_2}^{+}<{{\mathrm{MnO}}_4}^{-},$                           

(D) ${\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-}<{{\mathrm{MnO}}_4}^{-}<{{\mathrm{VO}}_2}^{+}$

At $300°\mathrm{C}, {\mathrm{FeCl}}_3 :$

1. Decomposes into ${\mathrm{FeCl}}_2 \mathrm{and} {\mathrm{Cl}}_2.$               

2. Decomposes into $\mathrm{Fe} \mathrm{and} {\mathrm{Cl}}_2.$

3. Sublimes go give liquid ${\mathrm{FeCl}}_3$                         

4. Sublimes to give gaseous dimmer ${\left({\mathrm{FeCl}}_3\right)}_2.$

Anhydrous ferric chloride is prepared by

(1) Heating hydrated ferric chloride at a high temperature in a stream of air.

(2) Heating metallic iron in a stream of dry chlorine gas.

(3) Reaction of ferric oxide with HCl (aq).

(4) Reaction of metallic iron with HCl (aq).

Select the correct statement :

(1) ${\mathrm{PH}}_3$ reduces ${\mathrm{AgNO}}_3$ to metallic Ag.

(2) Organic tissues turn ${\mathrm{AgNO}}_3$ black by reducing it to Ag.

(3) $\mathrm{AgCN}$is soluble in $\mathrm{KCN}$.

(4) All are correct statements.

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

1. ${{\mathrm{BrO}}_3}^{‐}, {\mathrm{MnO}}_2$                                     

2. ${{\mathrm{BrO}}_4}^{‐}, {\mathrm{Mn}}^{2+}$

3. ${\mathrm{Br}}_2, {\mathrm{MnO}}_2$                                         

4. ${\mathrm{Br}}_2{\mathrm{O}}^{‐}, {{\mathrm{MnO}}_4}^{2‐}$

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

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

(D) PtCl₂, NiCl₂