Amongst the following identify the species with an atom in (+6) oxidation state.

1. Mn${\mathrm{O}}_4^{-}$

2. Cr$(\mathrm{CN}{)}_{}^{3-}6$

3. Ni${\mathrm{F}}_6^{2-}$

4. CrO₂Cl₂

A metallic oxide contains 20% oxygen. The equivalent weight of metal is

1. 12

2. 16

3. 32

4. 64

Which one is correct about CH₂ = CCl₂?

(1) Both carbon are in +2 oxidation state.

(2)  Both carbon are in +- oxidation state.

(3) Once carbon has +2 and other -2 oxidation state.

(4) The average oxidation number of carbon is +1.

What is the equivalent weight of H₃PO₃ in the following disproportionation reaction:-

H₃PO₃ $\to$H₃PO₄ + PH₃

1. $\frac{M}{6}$   

 2. $\frac{M}{2}$ 

3.  $\frac{2M}{3}$ 

 4. $\frac{M}{3}$

25.0 g of FeSO₄.7H₂O was dissolved in water containing dilute H₂SO₄, and the volume was made up to 1.0 L. 25.0 mL of this solution required 20 mL of an N/10 KMnO₄ solution for complete oxidation. The percentage of FeSO₄^. 7H₂O in the acid solution is

(1) 78%

(2) 98%

(3) 89%

(4) 79%

Which one of the following orders correctly represents the increasing acid strengths of the given acids?

(1) HOCl<HOClO<HOClO₂<HOClO₃

(2) HOClO<HOCl<HOClO₃<HOClO₂

(3) HOClO₂<HOClO₃<HOClO<HOCl

(4) HOClO₃>HOClO₂<HOClO<HOCl

The valency of Cr in the complex [Cr(H₂O)₄Cl₂]⁺ [MP PMT 2000]

(1) 1

(2) 3

(3) 5

(4) 6

Oxidation number of cobalt in K[Co(CO)₄] is

(1) + 1

(2) + 3

(3) – 1

(4) – 3

The oxidation number of phosphorus in Ba(H₂PO₂)₂ is [Kurukshetra CEE 1998; DCE 2004]

(1) – 1

(2) + 1

(3) + 2

(4) + 3

When KMnO₄ acts as an oxidising agent and ultimately forms ${\left[Mn{O}_4\right]}^{-2},Mn{O}_2,M{n}_2{O}_3,M{n}^{+2}$ then the number of electrons transferred in each case respectively is [AIEEE 2002]

(1) 4, 3, 1, 5

(2) 1, 5, 3, 7

(3) 1, 3, 4, 5

(4) 3, 5, 7, 1