Hydrogen Questions — NEET Chemistry

Q1

Methane reacts with steam at 1273 K in the presence of nickel catalyst to form :

A CO and

\mathrm{H}_2 \mathrm{O}

B

\mathrm{CO}_2

and

\mathrm{H}_2

C

\mathrm{CO}

and

\mathrm{H}_2

D

\mathrm{CO}_2

and

\mathrm{H}_2 \mathrm{O}

Correct Answer

Option C

Solution

\mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{~g}) \xrightarrow[(1273 \mathrm{~K})]{\mathrm{Ni}} \mathrm{CO}+3 \mathrm{H}_2

(Used for industrial preparation of dihydrogen gas)

Q2

In the neutral or faintly alkaline medium, KMnO 4 oxidises iodide into iodate. The change in oxidation state of manganese in this reaction is form

A +7 to +4

B +6 to +4

C +7 to +3

D +6 to +5

Correct Answer

Option A

Solution

In neutral or faintly alkaline solution.

\mathop {2MnO_4^ - }\limits^{ + 7} + {H_2}O + \mathop {{I^ - }}\limits_{(iodide)}^{ - 1} \to \mathop {2Mn{O_2}}\limits^{ + 4} + 2O{H^ - } + \mathop {IO_3^ - }\limits_{(iodate)}^{ + 5}

Manganese (Mn) oxidation state change from +7 to +4.

Q3

Tritium, a radioactive isotope of hydrogen, emits which of the the following particles?

A Neutron (n)

B Beta (

\beta

-

)

C Alpha (

\alpha

)

D Gamma (

\gamma

)

Correct Answer

Option B

Solution

Hydrogen has three isotopes : protium(

_1^1

H) deuterium(

_1^2

H or D) and tritium (

_1^3

H or T).

Of these isotopes, only tritium is radioactive and emits low energy $\beta$ $-$ particles (t 1/2 , 12.33 years).

Q4

The method used to remove temporary hardness of water is :

A Ion-exchange method

B Synthetic resins method

C Calgon’s method

D Clark’s method

Correct Answer

Option D

Solution

Clark's method used to remove temporary hardness of water Ca(HCO 3 ) 2 + Ca(OH) 2 $\to$ 2CaCO 3 + 2H 2 O

Q5

The structure of H 2 O 2 is

A spherical

B non-planar

C planar

D linear

Correct Answer

Option B

Solution

In H 2 O 2 , the O–H groups are not in the same plane.

So it has non-planar structure.

It has a half-opened book structure in which the two O–H groups lie on the two pages of the book.

The angle between two pages of the book is 94 o and H–O–O bond angle is 97 o .

Q6

Which of the following statements about hydrogen is incorrect?

A Hydronium ion, H 3 O + exists freely in solution.

B Dihydrogen does not act as a reducing agent.

C Hydrogen has three isotopes of which tritium is the most common.

D Hydrogen never acts as cation in ionic salts.

Correct Answer

Option B

Solution

Dihydrogen acts as a powerful reducing agent and reduces metal oxides such as CuO, ZnO, PbO and Fe 3 O 4 to their respective metals.

CuO + H 2 $\to$ Cu + H 2 O ZnO + H 2 $\to$ Zn + H 2 O Fe 3 O 4 + 4H 2 $\to$ 3Fe + 4H 2 O Hydrogen has three isotopes of which protium is the most common and tritium is radioactive.

Q7

The water having more dissolved O2 is :

A boiling water

B water at 80

^\circ

C

C polluted water

D water at 4

^\circ

C

Correct Answer

Option D

Solution

On heating concentration of O2 in water decreases. So boiling water and water at 80

^\circ

C having less O2 concentration. Polluted water also having less O2 concentration. So water at 4

^\circ

C having maximum O2 concentration.

Q8

Which of the following can be used to prevent the decomposition of

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

?

A Urea

B Formaldehyde

C Formic acid

D Ethanol

Correct Answer

Option A

Solution

Urea is used as a stabilizer for the storage of

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

.

Q9

The normal rain water is slightly acidic and its

\mathrm{pH}

value is

5.6

because of which one of the following?

A

\mathrm{N}_{2} \mathrm{O}_{5}+\mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{HNO}_{3}

B

2 \mathrm{SO}_{2}+\mathrm{O}_{2}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{H}_{2} \mathrm{SO}_{4}

C

4 \mathrm{NO}_{2}+\mathrm{O}_{2}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow 4 \mathrm{HNO}_{3}

D

\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{H}_{2} \mathrm{CO}_{3}

Correct Answer

Option D

Solution

Normally rain water has a pH of 5.6 due to presence of H+ ions formed by the reaction of rain water with carbon dioxide present in the atmosphere.

\begin{aligned} & \mathrm{H}_2 \mathrm{O}(\mathrm{l})+\mathrm{CO}_2(\mathrm{~g}) \leftrightharpoons \mathrm{H}_2 \mathrm{CO}_3(\mathrm{aq}) \\\\ & \mathrm{H}_2 \mathrm{CO}_3(\mathrm{aq}) \leftrightharpoons \mathrm{H}^{+}(\mathrm{aq})+\mathrm{HCO}_3^{-}(\mathrm{aq}) \end{aligned}

Q10

The isotopes of hydrogen are :

A Tritium and protium only

B Protium and Deuterium only

C Protium, deuterium and tritium

D Deuterium and tritium only

Correct Answer

Option C

Solution

Isotopes of hydrogen are (1) Protium (1H1) (2) Deuterium (1H2) (3) Tritium (1H3)