An element that does not show variable oxidation state is:

1.	Fe	2.	Mn
3.	Cu	4.	Zn

A pair among the following that has both coloured ions in the aqueous solution is-
(At. no : Sc =21, Ti = 22, Ni = 28, Cu = 29, Co = 27)

 The increasing order of oxidising power among the following species is :

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

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

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

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

The values of X, Y, P, and Q are, respectively:
   

1. ${\mathrm{MnO}}_3^{+}$, Mn₂O₇, conc. H₂SO₄, and K₂MnO₄

2. K₂MnO₄, conc. H₂SO₄, Mn₂O₇, and ${\mathrm{MnO}}_3^{+}$

3. Na₂CO₃, MnO₂, K₂MnO₄, and Mn₂O₇

4. H⁺, K₂MnO₄, ${\mathrm{MnO}}_3^{+}$, and Mn₂O₇

Which of the following statements is false? 

The incorrect statement among the following is:  

Iron does not get oxidised in:

Which one of the following is a diamagnetic ion?

The oxidation state of chromium in the final product formed by the reaction between KI and acidified potassium dichromate solution will be:

1. +2

2. +3

3. +4

4. +6

The lanthanide contraction is responsible for the fact that:

1. Zr and Y have about the same radius .

2. Zr and Zn have the same oxidation state.  

3. Zr and Hf have about the same atomic radius .

4. Zr and Nb have a similar oxidation state.