When hydrogen peroxide is shaken with an acidified solution of potassium dichromate
in presence of ether, the ethereal layer turns blue due to the formation of

1. ${\mathrm{Cr}}_2{\mathrm{O}}_3<mspace\; width="1em"></mspace>$

2. ${\mathrm{CrO}}_4^{2-}$

3. $\mathrm{CrO}{\left({\mathrm{O}}_2\right)}_2$

4. None of these

In solid ice, oxygen atom is surrounded

1. tetrahedrally by 4 hydrogen atoms

2. octahedrally by 2 oxygen and 4 hydrogen atoms

3. tetrahedrally by 2 hydrogen and 2 oxygen atoms

4. octahedrally by 6 hydrogen atoms

The type of H-bonding present in ortho nitro phenol and p-nitro phenol are respectively

1. inter molecular H-bonding and intra molecular H-bonding

2. intra molecular H-bonding and inter molecular H-bonding

3. intra molecular H - bonding and no H - bonding

4. intra molecular H - bonding and intra molecular H - bonding

Heavy water is used as

1. moderator in nuclear reactions

2. coolant in nuclear reactions

3. both (1) and (2)

4. none of these

Which of the following pairs of substances on reaction will not evolve gas?

1. Iron, and ${\mathrm{H}}_2{\mathrm{SO}}_4$ (aq)

2. Iron, and steam

3. Copper, and HCl(g)

4. Sodium, and ethyl alcohol

Which transition metal is used for the reduction of steam to hydrogen?

1. Mg

2. Fe

3. Sc

4. Pt

The percentage by weight of Hydrogen of $H_2{O}_2$ is:

(1) 5.88

(2) 6.25

(3) 25

(4) 50

Hard water can be produced by -

(1) Saturation of water with CaSO₄

(2) Addition of $N{a}_{2}S{O}_4$  to water

(3) Saturation of water with CaCO₃

(4) Saturation of water with MgCO₃

When zeolite (hydrated sodium aluminium silicate) is treated with hard water the sodium ions are exchanged with:

(1) $H^{+}ions$

(2) $C{a}^{2+}$ ions

(3) $S{O}_4^{2-}$ ions

(4) $O{H}^{-}$ ions

The volume strength of 1.5 N H${}_2$O${}_2$ solution is:

(1) 4.8

(2) 8.4

(3) 3.0

(4) 8.0