Some p-Block Elements MCQs – Group 13 and 14 Class 11
Some p-Block Elements MCQs – Group 13 & Group 14 (Class 11 Chemistry)
Course: CBSE Class 11 Chemistry – MCQs with Answers and Explanations
Section: Inorganic Chemistry – MCQ Titles
The following 50 Multiple Choice Questions (MCQs) are strictly based on the NCERT chapter “Some p-Block Elements”, covering Group 13 (Boron family) and Group 14 (Carbon family). The questions are arranged section-wise and supported with clear, concept-clearing explanations, making them ideal for CBSE Class 11 board exam preparation.
Section A: Introduction to p-Block Elements
1. p-Block elements are those in which the last electron enters the
A. s-orbital
B. p-orbital
C. d-orbital
D. f-orbital
Answer: B
Explanation: p-Block elements have their valence electrons in p-orbitals.
2. p-Block elements are present in groups
A. 1 and 2
B. 3 to 12
C. 13 to 18
D. 17 and 18 only
Answer: C
Explanation: Groups 13–18 constitute the p-block.
3. p-Block elements show maximum diversity because they include
A. only metals
B. only non-metals
C. metals, non-metals and metalloids
D. noble gases only
Answer: C
Explanation: p-Block has the widest variety of elements.
Section B: Group 13 – Boron Family (General Trends)
4. Group 13 elements have general electronic configuration
A. ns¹
B. ns²
C. ns²np¹
D. ns²np²
Answer: C
Explanation: One p-electron gives configuration ns²np¹.
5. Which element of Group 13 is a metalloid?
A. Aluminium
B. Gallium
C. Boron
D. Indium
Answer: C
Explanation: Boron shows metalloid behaviour.
6. Metallic character in Group 13
A. decreases down the group
B. increases down the group
C. remains constant
D. increases across the period
Answer: B
Explanation: Atomic size increases down the group, enhancing metallic nature.
Section C: Anomalous Behaviour of Boron
7. Boron shows anomalous behaviour due to
A. large size
B. low ionisation enthalpy
C. small size and high charge density
D. presence of d-orbitals
Answer: C
Explanation: Small size and high polarising power cause anomaly.
8. Which property is NOT shown by boron?
A. Formation of covalent compounds
B. Formation of ionic compounds
C. High melting point
D. Formation of electron-deficient compounds
Answer: B
Explanation: Boron forms covalent compounds only.
9. Boron does not form B³⁺ ion because
A. it is non-metal
B. ionisation enthalpy is very high
C. it has low electronegativity
D. it has only three electrons
Answer: B
Explanation: Removal of three electrons requires very high energy.
Section D: Compounds of Boron
10. Borax has the chemical formula
A. Na₂B₄O₇·10H₂O
B. Na₂CO₃·10H₂O
C. NaBO₂
D. B₂O₃
Answer: A
Explanation: Borax is sodium tetraborate decahydrate.
11. Boric acid acts as
A. strong acid
B. weak monobasic acid
C. weak Lewis acid
D. strong base
Answer: C
Explanation: Boric acid accepts hydroxide ions (Lewis acid).
12. Hybridisation of boron in BF₃ is
A. sp
B. sp²
C. sp³
D. dsp²
Answer: B
Explanation: Three bond pairs around boron give sp² hybridisation.
Section E: Aluminium and Its Properties
13. Aluminium belongs to
A. s-block
B. d-block
C. p-block
D. f-block
Answer: C
Explanation: Aluminium is a Group 13 p-block metal.
14. Aluminium shows oxidation state of
A. +1 only
B. +2 only
C. +3 only
D. +1 and +3
Answer: C
Explanation: Aluminium mainly shows +3 oxidation state.
15. Aluminium is protected from corrosion by
A. rusting
B. coating of oxide layer
C. galvanisation
D. alloying
Answer: B
Explanation: Thin Al₂O₃ layer prevents further oxidation.
16. Aluminium chloride exists as dimer (Al₂Cl₆) because
A. aluminium is large
B. aluminium has low electronegativity
C. aluminium is electron-deficient
D. chlorine is small
Answer: C
Explanation: Electron deficiency leads to dimer formation.
Section F: Group 14 – Carbon Family (General Trends)
17. Group 14 elements have general electronic configuration
A. ns²np¹
B. ns²np²
C. ns²np³
D. ns²np⁴
Answer: B
Explanation: Two electrons in p-subshell.
18. Which element of Group 14 is non-metal?
A. Silicon
B. Germanium
C. Tin
D. Carbon
Answer: D
Explanation: Carbon is a non-metal.
19. Metallic character in Group 14
A. decreases down the group
B. increases down the group
C. remains constant
D. decreases across the period
Answer: B
Explanation: Heavier elements are more metallic.
Section G: Anomalous Behaviour of Carbon
20. Carbon shows anomalous behaviour because of
A. large size
B. low electronegativity
C. absence of d-orbitals and strong C–C bonding
D. metallic nature
Answer: C
Explanation: Strong catenation and lack of d-orbitals make carbon unique.
21. Catenation is maximum in
A. carbon
B. silicon
C. germanium
D. tin
Answer: A
Explanation: Strong C–C bonds give maximum catenation.
22. Carbon does not form C⁴⁺ ion because
A. it is non-metal
B. ionisation enthalpy is very high
C. it has small size
D. it forms covalent bonds
Answer: B
Explanation: Removing four electrons requires very high energy.
Section H: Allotropes of Carbon
23. Which of the following is crystalline allotrope of carbon?
A. Coal
B. Coke
C. Diamond
D. Charcoal
Answer: C
Explanation: Diamond has a well-defined crystal structure.
24. In diamond, carbon is
A. sp hybridised
B. sp² hybridised
C. sp³ hybridised
D. unhybridised
Answer: C
Explanation: Each carbon forms four sigma bonds.
25. Graphite conducts electricity because
A. it has free protons
B. it has delocalised electrons
C. it is ionic
D. it contains metal atoms
Answer: B
Explanation: Delocalised π-electrons move freely.
Section I: Oxides of Group 14 Elements
26. CO₂ is
A. acidic oxide
B. basic oxide
C. amphoteric oxide
D. neutral oxide
Answer: A
Explanation: CO₂ forms carbonic acid in water.
27. SiO₂ has a
A. simple molecular structure
B. giant covalent structure
C. ionic structure
D. metallic structure
Answer: B
Explanation: SiO₂ has a three-dimensional network.
28. Which oxide is amphoteric?
A. CO₂
B. SiO₂
C. SnO₂
D. PbO₂
Answer: C
Explanation: SnO₂ reacts with both acids and bases.
Section J: Hydrides of Group 14 Elements
29. General formula of hydrides of Group 14 is
A. EH₂
B. EH₃
C. EH₄
D. EH₅
Answer: C
Explanation: Tetrahydrides are formed by Group 14 elements.
30. Stability of hydrides of Group 14
A. increases down the group
B. decreases down the group
C. remains constant
D. increases across the period
Answer: B
Explanation: Bond strength decreases with size.
31. Most stable hydride among Group 14 is
A. CH₄
B. SiH₄
C. GeH₄
D. SnH₄
Answer: A
Explanation: C–H bond is strongest.
Section K: Halides of Group 13 and 14
32. BF₃ is a
A. strong base
B. Lewis acid
C. Lewis base
D. neutral molecule
Answer: B
Explanation: Electron-deficient boron accepts electron pairs.
33. Which halide shows maximum covalent character?
A. BCl₃
B. AlCl₃
C. GaCl₃
D. InCl₃
Answer: A
Explanation: Small size of boron increases covalency.
34. SnCl₄ is
A. ionic
B. covalent
C. polymeric
D. metallic
Answer: B
Explanation: Higher oxidation state favours covalent nature.
Section L: Oxidation States and Inert Pair Effect
35. Inert pair effect is observed in
A. Group 13 and 14
B. s-block only
C. Group 1 and 2
D. noble gases
Answer: A
Explanation: ns² electrons show reluctance to participate.
36. Due to inert pair effect, oxidation state +1 becomes stable in
A. boron
B. aluminium
C. gallium
D. thallium
Answer: D
Explanation: Thallium shows stable +1 oxidation state.
37. In Group 14, stability of +2 oxidation state increases down the group due to
A. catenation
B. inert pair effect
C. high electronegativity
D. metallic bonding
Answer: B
Explanation: ns² electrons remain inert.
Section M: Conceptual NCERT-Based MCQs
38. Maximum covalent character is shown by
A. NaCl
B. MgCl₂
C. AlCl₃
D. KCl
Answer: C
Explanation: Small highly charged Al³⁺ ion polarises Cl⁻ strongly.
39. Which element forms electron-deficient compounds?
A. Carbon
B. Boron
C. Aluminium
D. Silicon
Answer: B
Explanation: Boron compounds often have incomplete octet.
40. Which compound acts as Lewis acid?
A. NH₃
B. H₂O
C. BF₃
D. OH⁻
Answer: C
Explanation: BF₃ accepts an electron pair.
Section N: High-Order Thinking MCQs
41. Which compound is used as a catalyst in Friedel–Crafts reactions?
A. BCl₃
B. AlCl₃
C. GaCl₃
D. InCl₃
Answer: B
Explanation: AlCl₃ is a strong Lewis acid catalyst.
42. The hardest allotrope of carbon is
A. graphite
B. diamond
C. fullerene
D. charcoal
Answer: B
Explanation: Strong sp³ network makes diamond hardest.
43. Which oxide is basic in nature?
A. CO₂
B. SiO₂
C. PbO
D. SnO₂
Answer: C
Explanation: PbO shows basic character.
Section O: Final Conceptual MCQs
44. Which Group 13 element has maximum ionisation enthalpy?
A. Boron
B. Aluminium
C. Gallium
D. Indium
Answer: A
Explanation: Small size of boron leads to high ionisation enthalpy.
45. Which Group 14 element forms maximum number of compounds?
A. Silicon
B. Carbon
C. Germanium
D. Tin
Answer: B
Explanation: Carbon shows maximum catenation.
46. Which allotrope of carbon is used as lubricant?
A. Diamond
B. Graphite
C. Charcoal
D. Coke
Answer: B
Explanation: Layered structure allows easy sliding.
47. Which compound is used in making glass?
A. Na₂CO₃
B. CaCO₃
C. SiO₂
D. B₂O₃
Answer: C
Explanation: Silica is main component of glass.
48. Which element shows both metallic and non-metallic behaviour?
A. Aluminium
B. Boron
C. Carbon
D. Tin
Answer: B
Explanation: Boron is a metalloid.
49. Down the Group 14, bond energy of E–H bond
A. increases
B. decreases
C. remains same
D. first increases then decreases
Answer: B
Explanation: Larger size weakens E–H bond.
50. The most important reason for diversity in p-block is
A. same valency
B. presence of metals only
C. variable oxidation states and bonding
D. small atomic size
Answer: C
Explanation: p-Block elements show wide range of oxidation states and structures.
✅ Completion Note
This completes a fully NCERT-aligned, CBSE-standard set of 50 MCQs on Some p-Block Elements (Group 13 and 14), ideal for concept clarity, systematic revision, and board exam preparation.