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Assertion : The $O - O$ bond length of $H_{2} O_{2}$ is shorter than that of $O_{2} F_{2} .$

Reason : $H_{2} O_{2}$ is an ionic compound.

A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion C. If the assertion is true but the reason is false D. If both the assertion and reason are false

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Explanation

(D). The lone pairs of electrons on the O atoms are strongly attracted by the electronegative F

atoms. As a result, lone pair-lone pair repulsion of the two oxygen atoms is far less in $O_{2} F_{2}$

than in $H_{2} O_{2}$ . As a result, $O - O$ bond length is $O_{2} F_{2}$ (1.22 $\overset{\circ}{A}$ ) is much shorter than in

$H_{2} O_{2}$ (1.48 $\overset{\circ}{A}$ )

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Of the two solvents $H_{2} O a n d D_{2} O$ , NaCl dissolves:

A.

equally in both

B.

only in $H_{2} O$

C.

more in $D_{2} O$

D.

more in $H_{2} O$

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Explanation

In order for a ionic compound to be soluble in a solvent it has to be first get in between the solvent molecules, for this in case of water molecules it has to break $O - H$ bonds.

However in case of Heavy water the

O - D

bond is slightly stronger and hence cannot be broken as easily as

O - H

bond, hence the

N a

and

C l

are less solvated making them less soluble in heavy water.

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Heavy water is ......% heavier than ordinary water

A.

11

B.

20

C.

25

D.

15

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Explanation

wt of D₂0 = 20 ,wt of H₂O = 18

gap = 2 gram

% wt = (2 /18) x 100 = 11%

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The decomposition of $H_{2} O_{2}$ can be slowed down by the addition of small amount of phosphoric acid which act as:

A.

stopper

B.

detainer

C.

inhibitor

D.

promoter

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Explanation

The chemical substance added to another substance, to slow down a reaction or to prevent an unwanted chemical change is called inhibitor. The decomposition of hydrogen peroxide. Unwanted chemical change can be slowed down by the addition of a small amount of acetamide. The latter acts as an inhibitor.

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The hair dyes available in the market generally contain two bottles, one containing the dye and the other hydrogen peroxide. Before applying the dye, the two solutions are mixed. The hydrogen peroxide:

A.

is added to dilute the solution of the dye

B.

oxidizes the dye to give the desired color

C.

reduces the dye to give the desired color

D.

acidifies the solution of the dye

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Explanation

to oxidise the dye to give desired colour

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Benzene is oxidised by $H_{2} O_{2}$ in the presence of $F e S O_{4}$ to:

A.

phenol

B.

cyclohexane

C.

benzaldehyde

D.

benzoic acid

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The rubber foam is produced by passing oxygen through rubber foaming material. This oxygen is released from:

A.

nitric oxide

B.

hydrogen peroxide

C.

Water

D.

$C O_{2}$

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Explanation

Hydrogen peroxide is a foaming material to produce oxygen in Rubber foaming process....

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$H_{2} O_{2}$ is stored in:

A.

iron container after addition of stabilizer

B.

glass container after addition of stabilizer

C.

plastic container after the addition of stabilizer

D.

none of these

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Explanation

Hydrogen peroxide easily decomposes into water and oxygen and the decomposition speeds up in the presence of metallic impurities or strong bases and on exposure to light. Hence, it is stored in plastic container after addition of stabiliser.

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Acidified $K M n O_{4}$ is decolourised by:

A.

oxygen

B.

hydrogen

C.

nitric oxide

D.

nascent hydrogen

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Acidified solution of chromic acid on treatment with $H_{2} O_{2}$ yields:

A.

$C r O_{3} + H_{2} O + O_{2}$

B.

$C r_{2} O_{2} + H_{2} O + O_{2}$

C.

$C r O_{5} + H_{2} O + K_{2} S O_{4}$

D.

$H_{2} C r_{2} O_{7} + H_{2} O + O_{2}$

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Explanation

$K_{2} C r_{2} O_{7} + H_{2} S O_{4} \to K_{2} S O_{4} + H_{2} C r_{2} O_{7}$
$H_{2} C r_{2} O_{7} + 4 H_{2} O_{2} \to 2 C r O_{5} + 5 H_{2} O$

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