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

Which of the following is a result of the lanthanide contraction?

1. Zr and Y have nearly the same atomic radius.

2. Zr and Zn have the same oxidation state. 

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

4. Zr and Nb have similar oxidation states.