Hydrogen — Page 4 | NEET Chemistry

Q31

Which one of the following reactions indicates the reducing ability of hydrogen peroxide in basic medium?

A HOCl + H2O2

\to

H3O+ + Cl

-

+ O2

B PbS + 4H2O2

\to

PbSO4 + 4H2O

C 2MnO

_4^ -

+ 3H2O2

\to

2MnO2 + 3O2 + 2H2O + 2OH

-

D Mn2+ + H2O2

\to

Mn4+ + 2OH

-

Correct Answer

Option C

Solution

$2 \mathrm{Mn}\overset{+7}{\mathrm{O}_{4}^{-}}+3 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow$ $2 \mathrm{Mn}\overset{+4}{\mathrm{O}_{2}}+3 \mathrm{O}_{2}+2 \mathrm{H}_{2} \mathrm{O}+2 \mathrm{O} \overline{\mathrm{H}}$ In basic medium $\mathrm{MnO}_{4}^{-}$ is reduced to $\mathrm{MnO}_{2}$ , whereas in acidic medium it is reduced to $\mathrm{Mn}^{+2}$ .

Q32

Consider the following reaction:

2HSO_4^ - (aq)\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{(2)\,Hydrolysis}^{(1)\,Electrolysis}} 2HSO_4^ - + 2{H^ + } + A

The dihedral angle in product A in its solid phase at 110 K is :

A 104

^\circ

B 111.5

^\circ

C 90.2

^\circ

D 111.0

^\circ

Correct Answer

Option C

Solution

A should be $\mathrm{H}_{2} \mathrm{O}_{2}$ Structure of $\mathrm{H}_{2} \mathrm{O}_{2}$ is solid phase Dihedral angle $=90.2^{\circ}$

Q33

The highest industrial consumption of molecular hydrogen is to produce compounds of element :

A Carbon

B Nitrogen

C Oxygen

D Chlorine

Correct Answer

Option B

Solution

Hydrogen combines with nitrogen to produce Ammonia in Haber's process.

$\mathrm{N}_{2}(\mathrm{g})+3 \mathrm{H}_{2}(\mathrm{g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{g})$ In this process, iron oxide is used with small amounts of $\mathrm{K}_{2} \mathrm{O}$ and $\mathrm{Al}_{2} \mathrm{O}_{3}$ to increase the rate of attainment of equilibrium.

Optimum conditions for the production of ammonia are a pressure of $200 \mathrm{~atm}$ and a temperature of $700 \mathrm{~K}$ .

Earlier, iron was used as a catalyst with molybdenum as a promoter in this reaction.

Q34

The metal salts formed during softening of hardwater using Clark's method are :

A

\mathrm{Ca}(\mathrm{OH})_{2}

and

\mathrm{Mg}(\mathrm{OH})_{2}

B

\mathrm{CaCO}_{3}

and

\mathrm{Mg}(\mathrm{OH})_{2}

C

\mathrm{Ca}(\mathrm{OH})_{2}

and

\mathrm{MgCO}_{3}

D

\mathrm{CaCO}_{3}

and

\mathrm{MgCO}_{3}

Correct Answer

Option B

Solution

In Clark's method, calculated amount of lime is added to hard water.

It precipitates out calcium carbonate and magnesium hydroxide which can filtered off.

\begin{aligned} &\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow 2 \mathrm{CaCO}_{3} \downarrow+2 \mathrm{H}_{2} \mathrm{O} \\\\ &\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}+2 \mathrm{Ca}(\mathrm{OH})_{2} \rightarrow 2 \mathrm{CaCO}_{3} \downarrow+\mathrm{Mg}(\mathrm{OH})_{2}+2 \mathrm{H}_{2} \mathrm{O} \end{aligned}

Q35

Which of the given compounds can enhance the efficiency of hydrogen storage tank?

A SiH

_4

B Li/P

_4

C NaNi

_5

D Di-isobutylaluminium hydride

Correct Answer

Option C

Solution

Tanks of metal alloy like $\mathrm{NaNi}_{5}, \mathrm{Ti}{-\mathrm{TiH}_{2},} \mathrm{Mg}-{\mathrm{MgH}}_{2}$ are used for the storage of dihydrogen.

Q36

Which hydride among the following is less stable?

A NH

_3

B HF

C LiH

D BeH

_2

Correct Answer

Option D

Solution

The stability of hydrides depends on their bonding and the electronegativity difference between the elements.

The greater the electronegativity difference, the more stable the hydride.

Based on this, the order of stability of the given hydrides is: HF > NH

_3

> LiH > BeH

_2

Therefore, the less stable hydride among the given options is BeH

_2

.

Q37

Which of the following can reduce decomposition of

\mathrm{H}_{2} \mathrm{O}_{2}

on exposure to light :

A Urea

B Glass containers

C Alkali

D Dust

Correct Answer

Option A

Solution

Urea is a negative catalyst, which means that it slows down the rate of a chemical reaction.

In the case of hydrogen peroxide, urea absorbs the light that would otherwise cause it to decompose.

This prevents the reaction from happening, or at least slows it down significantly.

Q38

The single largest industrial application of dihydrogen is :

A Manufacture of metal hybrides

B Rocket fuel in space research

C In the synthesis of ammonia

D In the synthesis of nitric acid

Correct Answer

Option C

Solution

The single largest industrial application of dihydrogen is in the synthesis of ammonia which is mainly used in the manufacture of fertiliser.

Q39

Water does not produce CO on reacting with :

A C

B CH4

C C3H8

D CO2

Correct Answer

Option D

Solution

CO2 + H2O $\to$ H2CO3 C + H2O(steam) $\to$ CO + H2 CH4 + H2O $\to$ CO + 3H2 C3H8 + H2O $\to$ 3CO + H2

Q40

Given below are two statements : Statement I : The process of producing syn-gas is called gasification of coal. Statement II : The composition of syn-gas is CO + CO2 + H2 (1 : 1 : 1) In the light of the above statements, choose the most appropriate answer from the options given below :

A Statement I is false but Statement II is true

B Statement I is true but Statement II is false

C Both Statement I and Statement II are false

D Both Statement I and Statement II are true

Correct Answer

Option B

Solution

The process of producing syn-gas from coal is called gasification of coal.

Syn-gas having composition of CO & H2 in 1 : 1