$H_2{O}_{\mathrm{2<mspace\; width="1em"></mspace>}}$on oxidation gives:

1. $O^{-2}$

2. $O{H}^{-}$

3. $O_2^{-}$

4. $O_2$

Pure water can be obtained from sea water by:

1.  Centrifugation
2.  Plasmolysis
3.  Reverse osmosis
4.  Sedimentation

The pair that on reaction will not evolve $H_2$ gas is  

1.  Copper and HCl (aqueous)
2.  Iron and steam
3.  Iron and $H_{2}S{O}_4$ (aqueous)
4.  Sodium and ethyl alcohol

Some statements about water are given below:
 

Which of the above statements are correct?

1. (a), (b), and (c)

2. (b) and (c)

3. (a) and (c)

4. (a) and (b)

The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order:

1. $L{i}^{+}<K^{+}<N{a}^{+}<R{b}^{+}$

2. $R{b}^{+}<K^{+}<N{a}^{+}<L{i}^{+}$

3. $K^{+}<N{a}^{+}<R{b}^{+}<L{i}^{+}$

4. $N{a}^{+}<L{i}^{+}<K^{+}<R{b}^{+}$

The reaction of aqueous KMnO₄ with H₂O₂ in acidic condition gives:
1. $M{n}^{4+}$ $and$ $O_2$
2. $M{n}^{2+}$ $and$ $O_2$
3. $M{n}^{2+}$ $and$ $O_3$
4. $M{n}^{4+}$ $and$ $Mn{O}_2$