Hydrogen — Page 4 | JEE Chemistry

Q31

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.

Q32

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.

Q33

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

Q34

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

Q35

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Heavy water is used for the study of reaction mechanism. Reason (R) : The rate of reaction for the cleavage of O - H bond is slower than that of O - D bond. Choose the most appropriate answer from the options given below :

A Both (A) and (R) are true but (R) is not the true explanation of (A).

B Both (A) and (R) are true and (R) is the true explanation of (A).

C (A) is false but (R) is true.

D (A) is true but (R) is false.

Correct Answer

Option D

Solution

D2O in used for the study of reaction mechanism. Rate of reaction for the cleavage of O-H bond > O-D bond.

Q36

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Loss of electron from hydrogen atom results in nucleus of

\sim 1.5 \times 10^{-3} \mathrm{pm}

size. Reason R : Proton

\left(\mathrm{H}^{+}\right)

always exists in combined form. In the light of the above statements, choose the most appropriate answer from the options given below:

A Both

\mathbf{A}

and

\mathbf{R}

are correct and

\mathbf{R}

is the correct explanation of

\mathbf{A}

B A is correct but R is not correct

C A is not correct but R is correct

D Both

\mathbf{A}

and

\mathbf{R}

are correct but

\mathbf{R}

is NOT the correct explanation of

\mathbf{A}

Correct Answer

Option D

Solution

Size of nucleus is of order $1.5 \times 10^{-15} \mathrm{~m}$ or $1.5 \times 10^{-3} \mathrm{pm}$ $\mathrm{H}^{+}$ always exists in combined form.

There is no relation between two statements and hence option (D) is the answer.

Q37

Given below are two statements : Statement I : H2O2 can act as both oxidising and reducing agent in basic medium. Statement II : In the hydrogen economy, the energy is transmitted in the form of dihydrogen. In the light of the above statements, choose the correct answer from the options given below :

A Both statement I and statement II are false

B Statement I is false but statement II is true

C Statement I is true but statement II is false

D Both statement I and statement II are true

Correct Answer

Option D

Solution

Oxidising action in basic medium 2Fe2+ + H2O2 $\to$ 2Fe3+ + 2OH– Reducing action in basic medium I2 + H2O2 + 2OH– $\to$ 2I– + 2H2O + O2 Advantage of hydrogen economy is that energy is transmitted in the form of dihydrogen and not as electric power

Q38

Match List I with List II .tg .tg List I List II A. Cobalt catalyst I.

\mathrm{(H_2+Cl_2)}

production B. Syngas II. Water gas production C. Nickel catalyst III. Coal gasification D. Brine solution IV. Methanol production Choose the correct answer from the options given below :

A A-IV, B-III, C-I, D-II

B A-IV, B-III, C-II, D-I

C A-II, B-III, C-IV, D-I

D A-IV, B-I, C-II, D-III

Correct Answer

Option B

Solution

(A) Hydrogen reacts with carbon monoxide in presence of cobalt catalyst to give methanol

2 \mathrm{H}_{2}(\mathrm{~g})+\mathrm{CO}(\mathrm{g}) \stackrel{\text{ cobalt catalyst }}{\longrightarrow} \mathrm{CH}_{3} \mathrm{OH}(\mathrm{I})

(B) Syn gas is produced from coal and the process is called coal gasification.

\mathrm{C}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \stackrel{1270 \mathrm{~K}}{\longrightarrow} \underset{(\text{ syn gas) }}{\mathrm{CO}(\mathrm{g})+\mathrm{H}_{2}(\mathrm{~g})}

(C) Reaction of steam with hydrocarbons or coke at high temperature in presence of nickel catalyst gives a mixture of $\mathrm{CO}$ and $\mathrm{H}_{2}$ , called water gas

\mathrm{CH}_{4}(\mathrm{~g})+\mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \underset{{\mathrm{Ni}}}{\stackrel{1270 \mathrm{~K}}{\longrightarrow}}\underset{(\text{ water gas })}{\mathrm{CO}(\mathrm{g})+3 \mathrm{H}_{2}(\mathrm{~g})}

(D) Electrolysis of brine solution produces $\mathrm{H}_{2}$ gas at cathode and $\mathrm{Cl}_{2}$ gas at anode $\mathrm{NaCl}(\mathrm{aq}) \longrightarrow \mathrm{Na}^{+}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq})$ Cathode : $2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l})+2 \mathrm{e}^{-} \longrightarrow \mathrm{H}_{2}(\mathrm{~g})+2 \mathrm{OH}^{-}(\mathrm{aq})$ Anode : $2 \mathrm{Cl}^{-}(\mathrm{aq}) \longrightarrow \mathrm{Cl}_{2}(\mathrm{~g})+2 \mathrm{e}^{-}$

Q39

The INCORRECT statement(s) about heavy water is (are) (A) used as a moderator in nuclear reactor (B) obtained as a by-product in fertilizer industry (C) used for the study of reaction mechanism (D) has a higher dielectric constant than water Choose the correct answer from the options given below :

A (D) only

B (B) and (D) only

C (B) only

D (C) only

Correct Answer

Option A

Solution

Heavy water (D2O) is obtained as a by-product in the fertilizer industry.

It is used as a moderator in nuclear reactors and for the study of the reaction mechanisms.

Its dielectric constant is lower than that of H2O.

Q40

Given below are two reactions, involved in the commercial production of dihydrogen (H

_2

). The two reactions are carried out at temperature "T

_1

" and "T

_2

", respectively

C(s) + {H_2}O(g)\overset{{{T_1}}}\longrightarrow CO(g) + {H_2}(g)

CO(g) + {H_2}O(g)\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{Catalyst}^{{T_2}}} C{O_2}(g) + {H_2}(g)

The temperatures T

_1

and T

_2

are correctly related as :

A T

_1

< T

_2

B T

_1

= T

_2

C T

_1

= 100 K, T

_2

= 1270 K

D T

_1

> T

_2

Correct Answer

Option D

Solution

These reactions are part of the water-gas shift reaction used in the industrial production of hydrogen.

The first reaction is the endothermic steam reforming of coal (carbon), while the second reaction is the exothermic water-gas shift reaction.

Carbon reacts with steam at high temperatures (around 1000°C or 1273 K) to form carbon monoxide and hydrogen: C(s) + H $_2$ O(g) $\xrightarrow[T_1]{}$ CO(g) + H $_2$ (g) Then carbon monoxide reacts with steam in the presence of a catalyst to produce carbon dioxide and more hydrogen: CO(g) + H $_2$ O(g) $\xrightarrow[Catalyst]{[T_2]}$ CO $_2$ (g) + H $_2$ (g) Since the first reaction is endothermic (absorbs heat), it requires a higher temperature to proceed than the second reaction, which is exothermic (releases heat).

Therefore, the temperature T $_1$ should be higher than T $_2$ .