Hydrogen MCQs – CBSE Class 11 Chemistry
Hydrogen MCQs – CBSE Class 11 Chemistry
Course: CBSE Class 11 Chemistry – MCQs with Answers and Explanations
Section: Physical Chemistry – MCQ Titles
The following 50 Multiple Choice Questions (MCQs) are strictly based on the NCERT chapter “Hydrogen”. The questions are arranged section-wise to ensure complete syllabus coverage and include clear, concept-clearing explanations, making them ideal for CBSE Class 11 board exam preparation.
Section A: Position of Hydrogen in the Periodic Table
1. Hydrogen is placed in the periodic table with
A. alkali metals only
B. halogens only
C. noble gases
D. alkali metals and halogens
Answer: D
Explanation: Hydrogen resembles alkali metals (one valence electron) and halogens (forms H⁻).
2. Electronic configuration of hydrogen is
A. 1s²
B. 1s¹
C. 2s¹
D. 2p¹
Answer: B
Explanation: Hydrogen has one electron in the 1s orbital.
3. Hydrogen differs from alkali metals because it
A. forms H⁺ ion
B. has one valence electron
C. is non-metallic
D. forms compounds
Answer: C
Explanation: Hydrogen is a non-metal, unlike alkali metals.
Section B: Occurrence and Isotopes of Hydrogen
4. The most abundant isotope of hydrogen is
A. protium
B. deuterium
C. tritium
D. hydronium
Answer: A
Explanation: Protium (¹H) constitutes about 99.98% of hydrogen.
5. Deuterium contains
A. one proton and one electron
B. one proton, one neutron, one electron
C. one proton and two neutrons
D. two protons
Answer: B
Explanation: Deuterium has one proton, one neutron, and one electron.
6. Tritium is
A. stable
B. radioactive
C. artificially radioactive
D. synthetic element
Answer: B
Explanation: Tritium (³H) is radioactive.
7. Heavy water is
A. H₂O
B. H₂O₂
C. D₂O
D. HD
Answer: C
Explanation: Heavy water contains deuterium instead of hydrogen.
Section C: Preparation of Hydrogen
8. Hydrogen is prepared in laboratory by reacting zinc with
A. nitric acid
B. sulphuric acid (dilute)
C. concentrated H₂SO₄
D. aqua regia
Answer: B
Explanation: Zn reacts with dilute acids to liberate H₂ gas.
9. Commercial method of hydrogen manufacture is
A. electrolysis of water
B. reaction of metals with acids
C. steam reforming of hydrocarbons
D. photochemical method
Answer: C
Explanation: Steam reforming of methane is widely used.
10. Hydrogen obtained from electrolysis of water is
A. impure
B. dry only
C. pure
D. mixed with oxygen
Answer: C
Explanation: Electrolysis gives pure hydrogen.
Section D: Properties of Hydrogen
11. Hydrogen gas is
A. heavier than air
B. colourless and odourless
C. toxic
D. highly soluble in water
Answer: B
Explanation: Hydrogen is colourless, odourless, and non-toxic.
12. Hydrogen burns in air producing
A. CO₂
B. CO
C. H₂O
D. H₂O₂
Answer: C
Explanation: Hydrogen combustion forms water.
13. Hydrogen acts as a reducing agent because it
A. gains electrons
B. loses electrons
C. gives oxygen
D. removes oxygen
Answer: D
Explanation: Hydrogen reduces metal oxides by removing oxygen.
14. Which metal oxide is reduced by hydrogen?
A. Na₂O
B. MgO
C. CuO
D. CaO
Answer: C
Explanation: Hydrogen reduces CuO to Cu.
Section E: Hydrides
15. Ionic hydrides are formed by
A. s-block elements
B. p-block elements
C. noble gases
D. transition metals
Answer: A
Explanation: Alkali and alkaline earth metals form ionic hydrides.
16. Which is an example of ionic hydride?
A. CH₄
B. NH₃
C. NaH
D. HCl
Answer: C
Explanation: Sodium hydride is ionic in nature.
17. Covalent hydrides are generally formed by
A. s-block elements
B. p-block elements
C. f-block elements
D. metals only
Answer: B
Explanation: Non-metals of p-block form covalent hydrides.
18. Metallic hydrides are formed by
A. alkali metals
B. halogens
C. transition metals
D. noble gases
Answer: C
Explanation: Transition metals form metallic hydrides.
Section F: Water and Its Properties
19. Water has maximum density at
A. 0°C
B. 4°C
C. 10°C
D. 100°C
Answer: B
Explanation: Due to hydrogen bonding structure.
20. The bent shape of water molecule is due to
A. sp hybridisation
B. sp² hybridisation
C. sp³ hybridisation
D. p orbital overlap
Answer: C
Explanation: Two lone pairs cause bending.
21. Hydrogen bonding in water results in
A. low boiling point
B. high boiling point
C. low density of ice
D. both B and C
Answer: D
Explanation: Hydrogen bonding explains these anomalies.
Section G: Hardness of Water
22. Temporary hardness of water is due to
A. chlorides
B. sulphates
C. bicarbonates
D. nitrates
Answer: C
Explanation: Bicarbonates of Ca and Mg cause temporary hardness.
23. Permanent hardness is removed by
A. boiling
B. filtration
C. adding washing soda
D. distillation only
Answer: C
Explanation: Washing soda precipitates Ca²⁺ and Mg²⁺ ions.
24. Hard water does not form lather with soap because
A. soap decomposes
B. Ca²⁺ forms insoluble salts
C. soap evaporates
D. water is acidic
Answer: B
Explanation: Calcium and magnesium form insoluble scum.
Section H: Hydrogen Peroxide (H₂O₂)
25. Oxidation state of oxygen in H₂O₂ is
A. −2
B. −1
C. 0
D. +1
Answer: B
Explanation: Peroxides contain oxygen in −1 state.
26. H₂O₂ acts as
A. only oxidising agent
B. only reducing agent
C. both oxidising and reducing agent
D. neutral compound
Answer: C
Explanation: It shows dual behaviour.
27. H₂O₂ decomposes to form
A. H₂ and O₂
B. H₂O and O₂
C. H₂ and H₂O
D. O₂ only
Answer: B
Explanation: 2H₂O₂ → 2H₂O + O₂.
28. Which catalyst is used for decomposition of H₂O₂?
A. MnO₂
B. Fe
C. Zn
D. Cu
Answer: A
Explanation: MnO₂ accelerates decomposition.
Section I: Uses of Hydrogen and Its Compounds
29. Hydrogen is used in manufacture of
A. ammonia
B. sulphuric acid
C. nitric acid
D. sodium hydroxide
Answer: A
Explanation: Haber process uses hydrogen.
30. Hydrogen is used as a fuel because
A. it is cheap
B. it produces no pollution
C. it releases high energy
D. it is easily stored
Answer: C
Explanation: Hydrogen has high calorific value.
31. Heavy water is used in nuclear reactors as
A. fuel
B. moderator
C. coolant
D. absorber
Answer: B
Explanation: It slows down neutrons.
Section J: Conceptual NCERT-Based MCQs
32. Hydrogen shows oxidation state of −1 in
A. H₂O
B. HCl
C. NaH
D. NH₃
Answer: C
Explanation: Hydrogen exists as hydride ion in metal hydrides.
33. Which compound contains hydrogen bonding?
A. CH₄
B. NH₃
C. H₂S
D. PH₃
Answer: B
Explanation: N–H bond allows hydrogen bonding.
34. Hydrogen does not show metallic properties because
A. small size
B. high ionisation enthalpy
C. low electronegativity
D. lack of valence electrons
Answer: B
Explanation: High ionisation energy prevents metallic behaviour.
35. Which hydride is polymeric?
A. CH₄
B. AlH₃
C. NH₃
D. H₂O
Answer: B
Explanation: Aluminium hydride shows polymeric structure.
Section K: Application-Based and Analytical MCQs
36. Hydrogen economy refers to
A. storage of hydrogen
B. use of hydrogen as fuel
C. production of hydrogen
D. purification of hydrogen
Answer: B
Explanation: It focuses on hydrogen as clean fuel.
37. Which gas is produced along with hydrogen in electrolysis of water?
A. Nitrogen
B. Carbon dioxide
C. Oxygen
D. Chlorine
Answer: C
Explanation: Oxygen is released at anode.
38. Hydrogen embrittlement occurs due to
A. formation of hydrides
B. corrosion
C. oxidation
D. polymerisation
Answer: A
Explanation: Metal becomes brittle due to hydride formation.
39. Which hydride is amphoteric?
A. NaH
B. LiH
C. BeH₂
D. CaH₂
Answer: C
Explanation: BeH₂ shows amphoteric behaviour.
40. Which isotope is used in thermonuclear reactions?
A. Protium
B. Deuterium
C. Tritium
D. Both B and C
Answer: D
Explanation: Deuterium and tritium are used in fusion.
Section L: Assertion-Type Conceptual MCQs
41. Hydrogen is combustible but does not support combustion because
A. it reacts with oxygen
B. it is non-metal
C. it is reducing agent
D. it lacks oxygen
Answer: A
Explanation: It burns in oxygen but does not help others burn.
42. Water is called universal solvent because
A. it dissolves all substances
B. it dissolves most ionic compounds
C. it is neutral
D. it has high density
Answer: B
Explanation: Due to high dielectric constant.
43. Which property of water is due to hydrogen bonding?
A. Colour
B. Taste
C. High boiling point
D. Density only
Answer: C
Explanation: Hydrogen bonding raises boiling point.
44. Hydrogen shows +1 oxidation state in
A. NaH
B. CaH₂
C. NH₃
D. LiH
Answer: C
Explanation: Hydrogen is bonded to non-metals.
45. Which compound is NOT a hydride?
A. NaH
B. CaH₂
C. H₂O
D. NH₃
Answer: C
Explanation: Water is oxide of hydrogen.
46. Hydrogen peroxide is stored in
A. iron containers
B. glass containers
C. plastic containers
D. copper containers
Answer: B
Explanation: Glass prevents catalytic decomposition.
47. Which hydride reacts violently with water?
A. NaH
B. CH₄
C. NH₃
D. PH₃
Answer: A
Explanation: Ionic hydrides react vigorously with water.
48. Which property of hydrogen resembles halogens?
A. Electropositivity
B. Forms H⁻ ion
C. Metallic nature
D. Low ionisation energy
Answer: B
Explanation: Hydrogen forms hydride ion like halogens.
49. Hydrogen gas is collected over water because it is
A. soluble in water
B. heavier than air
C. insoluble in water
D. toxic
Answer: C
Explanation: Hydrogen is almost insoluble in water.
50. Hydrogen is considered unique because it
A. is smallest element
B. shows variable oxidation states
C. resembles more than one group
D. all of these
Answer: D
Explanation: Hydrogen shows exceptional behaviour.
✅ Completion Note
This completes a fully NCERT-aligned, CBSE-standard set of 50 MCQs on Hydrogen, ideal for concept clarity, revision, and board exam preparation.