Hydrogen Test

Result

Hydrogen Test - 26

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Decomposition of $$H_{2}O_{2}$$ is retarded by__________.

A
Acetanilide

B
$$MnO_{2}$$

C
Zinc

D
finely divided metal

Solution

Decomposition of $$H_{2}O_{2}$$ can be retarded small amounts of acid, glycerol, alcohol, acetanilide.
Question 2
1 / -0

The $$O-O-H$$ bond angle in $$H_{2}O_{2}$$ is:

A
$$106^\circ$$

B
$$109^\circ 28'$$

C
$$120^\circ$$

D
$$94^\circ$$

Solution
Question 3
1 / -0

$$HCl$$ is added to the following oxides, which one would give $$H_{2}O_{2}$$?

A
$$BaO_{2}$$

B
$$MnO_{2}$$

C
$$PbO_{2}$$

D
$$NO_{2}$$

Solution

The laboratory preparation of hydrogen peroxide was based on the technique that Thenard used.

In this technique, barium nitrate, purified by recrystallization, was decomposed by heating in air in a porcelain retort. The resulting oxide was further oxidized by heating in a stream of oxygen to a dull red heat.

The barium peroxide which formed was then dampened, ground, and dissolved in hydrochloric acid.

A slight excess of sulfuric acid was then added to precipitate barium sulfate and regenerate hydrochloric acid. The procedure of barium peroxide solution and sulfate precipitation was repeated several times in the same solution to increase the peroxide concentration.
Reaction:

$$BaO_2.8H_2O + H_2SO_4 \rightarrow BaSO_4 + H_2O_2 + 8H_2O$$.
Question 4
1 / -0

The hydride ion $$H^{-}$$ is stronger base than hydroxide ion $$OH^{-}$$. Which of the following reaction will occur if sodium hydride $$(NaH)$$ is dissolved in water?

A
$$H^{-}(aq.)+H_{2}O \rightarrow H_{3}O^{-}$$

B
$$H^{-}(aq.)+H_{2}O(l) \rightarrow OH^{-}+H_{2}$$

C
$$H^{-}+H_{2}O \rightarrow$$ No reaction

D
None of the above

Solution

As hydride ion is stronger base, so it will react with water which acts as an acid. The reaction occurring is as follows:
$$H^{-}(aq.)+H_{2}O(l) \rightarrow OH^{-}+H_{2}$$.
Question 5
1 / -0

Which one of the following methods can be used to test the presence of water?

A
Smell the liquid

B
Add anhydrous copper sulphate and look for a colour change

C
Taste the liquid

D
Litmus paper with the solution

Solution

The reaction between anhydrous copper sulfate and water is reversible:
Anhydrous copper sulfate (white) $$+$$ water $$=$$ Hydrated copper sulfate (blue)
$$CuSO4 + 5H_2O \rightarrow CuSO_4.5H_2O$$.
White anhydrous amorphous copper sulfate combines with $$5$$ molecules of water to form hydrous blue copper sulfate (blue vitriol).
Question 6
1 / -0

Which is the accepted structure of $$H_{2}O_{2}$$ in gas phase?

A

B

C
both

D
none

Solution

Structure of $$H_{2}O_{2}$$ in gas phase.
Question 7
1 / -0

The equilibrium molecular structure of $$H_{2}O_{2}$$ is:

A
planar

B
linear

C
tetrahedral

D
non-planar, but not tetrahedral

E
cyclic

Solution

The equilibrium molecular structure of $$H_2O_2$$ is non planar
Question 8
1 / -0

Last molecule of $$H_{2}O$$ is evolved from $$H_{2}O_{2}$$ by:

A
crystallisation

B
evaporation

C
distillation under reduced pressure

D
electrolysis

Solution

The last molecule of water is separated from hydrogen peroxide by crystallization. $$90\%$$ solution of hydrogen peroxide is concentrated by cooling with solid carbon dioxide and ether bath. The crystals of hydrogen peroxide are separated, melted and refrozen.
Question 9
1 / -0

Density of water in the solid state is......... than the density of water in the liquid state.

A
higher

B
lower

C
same

D
none of these

Solution

The solid form of most substances is denser than the liquid phase so a block of most solids will sink in the liquid but a block of ice floats in liquid water because ice is less dense. Upon freezing the density of water decreases by about 9%. This is due to cooling of intermolecular vibrations allowing the molecules to form steady hydrogen bonds and locking into positions of hexagonal packing upon freezing to ice. These bonds are shorter in the crystal than in the liquid.
Question 10
1 / -0

Bond angle $$H-O-H$$ and $$H-O-O-H$$ in water and hydrogen peroxide respectively are :

A
$$104.5^\circ$$ in both

B
$$94.8^\circ$$ in both

C
$$104.5^\circ,\:94.8^\circ$$

D
$$94.8^\circ,\:104.5^\circ$$

Solution