Question

Class 11 Chemistry MCQ Question of The p-Block Elements with Answers?

Answer 1

Practice MCQ Questions for Class 11 with Answers consistently and score well in tests. We have incorporated the NCERT Class 11 Chemistry MCQ Questions of The P-Block Elements with Answers covering the whole syllabus. Refer to The P-Block Elements Class 11 MCQ Questions with Answers here alongside a point by point clarification. 

Elements of the gathering 13 to 18 in the periodic table are known as p-Block elements. In these components, the last electron goes to one of the outermost three p-orbital. Non-metals and metalloids only exist in the p-block. The heaviest element of each group of p-block is the most metallic in nature. 

Practice MCQ Questions for class 11 Chemistry Chapter-Wise

1. Red phosphorus is chemically less reactive because

(a) It does not contain P – P bonds
(b) It dos not contain tetrahedral P4 molecules
(c) It does not catch fire in air even upto 400°C
(d) It has a polymeric structure

2. Which of the following will not produce hydrogen gas?

(a) Reaction between Fe and dil. HCl
(b) Reaction between Zn and NaOH
(c) Reaction between Zn and conc. H₂SO₄
(d) Electrolysis of NaCl in Nelsons cell

3. Oxygen gas can be prepared from solid KMnO4 by:

(a) Dissolving the solid in dil. HCl
(b) Dissolving the solid in conc. H₂SO₄
(c) Treating the solid with H₂ gases
(d) Strongly heating the solid

4. In the upper layers of atmosphere ozone is formed:

(a) By action of electric discharge on oxygen molecule
(b) By action of ultraviolet rays on oxygen molecule
(c) By action of infrared rays on oxygen molecule
(d) Due to sudden drops of pressure

5. Which of the following oxidation states are most characteristic for lead and tin respectively?

(a) 2, 2
(b) 4, 2
(c) 2, 4
(d) 4, 4

6. Which of the following statements regarding ozone is not correct?

(a) The oxygen-oxygen bond length in ozone is identical with that of molecular oxygen
(b) The ozone is response hybrid of two structures
(c) The ozone molecule is angular in shape
(d) Ozone is used as a germicide and disinfectant for the purification of air

7. Ammonia gas can be dried by

(a) conc H₂SO₄
(b) P₂O₅
(c) CaCl₂
(d) Quick lime

8. In general, the Boron Trihaides act as

(a) Strong reducing agent
(b) Lewis Acids
(c) Lewis Bases
(d) Dehydrating Agents

9. On heating ozone, its volume.

(a) Increase to 1.5 times
(b) Decreases to half
(c) Remain uncharged
(d) Becomes double

10. Which metal is used in the thermal process because of its activity.

(a) Iron
(b) Copper
(c) Aluminum
(d) Zinc

11. Aluminum oxides is

(a) Acidic oxide
(b) Basic oxide
(c) Amphoteric oxide
(d) None of these

12. Which of the following is most abundant in the earth crust?

(a) Aluminium
(b) Thallium
(c) Boron
(d) Gallium

13. Which of the following properties of aluminium makes it useful for food packaging?

(a) Low density
(b) Non toxicity
(c) Good thermal conductivity
(d) Good electrical conductivity

14. The element which shows least metallic character is

(a) Boron
(b) Gallium
(c) Indium
(d) Aluminium

15. Which one of the following has the lowest m.p.?

(a) Ga
(b) B
(c) Al
(d) Tl

16. Thallium shows different oxidation states because

(a) of inert pair effect
(b) of its amphoteric character
(c) of its higher reactivity
(d) it is transition element

17. Which of the following does not react with aqueous NaOH?

(a) B
(b) Al
(c) Ga
(d) Tl

18. Boric acid is polymeric due to

(a) the presence of hydrogen bonds
(b) its acidic nature
(c) its monobasic nature
(d) its geometry

19. Bauxite is an ore of

(a) Aluminum
(b) Boron
(c) Carbono
(d) Gallium

20. The number of carbon atoms per unit cell of diamond unit cell is:-

(a) 4
(b) 8
(c) 6
(d) 1

21. Name the type of the structure of silicate in which one oxygen atom of [SiO₄]^4- is shared?

(a) Sheet silicate
(b) Pyrosilicate
(c) three dimensional silicate
(d) Linear chain silicate

22. Metal protected by a layer of its own oxide is:

(a) Al
(b) Ag
(c) Au
(d) Cu

23. Hoope's process is used in the refining of:

(a) Al
(b) Zn
(c) Ag
(d) Cu

24. Assertion : Al becomes passive in conc. HNO₃.
Reason : Conc. HNO₃ has no action on aluminium metal.

(a) If both assertion and reason are true and reason is the correct explanation of assertion
(b) If both assertion and reason are true but reason is not the correct explanation of assertion
(c) If assertion is true but reason is false
(d) If both assertion and reason are false

25. Chemically thermite is -

(a) Fe and Al
(b) Ferric oxide and aluminium powder
(c) Barium peroxide and magnesium powder
(d) Cu and aluminium

Answer 2

1. Answer : (d) It has a polymeric structure

Explanation: Red phosphorus is believed to have long chains of P₄ tetrahedrons, i.e., it is highly polymerized and hence is less reactive.

2. Answer : (c) Reaction between Zn and conc. H₂SO₄

Explanation: Concentrated sulphuric acid reacts with Zn to give SO₂ and not H₂

3. Answer : (d) Strongly heating the solid

Explanation: Oxygen gas can be prepared from solid KMnO₄ 250°C

2KMnO₄ → KMnO₄ + MnO₂ + O₂

4. Answer : (b) By action of ultraviolet rays on oxygen molecule

Explanation: In the upper layer of atmosphere, the Ultraviolet rays (UV rays) split the molecule of oxygen (O₂) nto its constituent 2 atoms. Each of the atom then combine with another oxygen (O₂) molecule which give O₃

5. Answer : (c) 2, 4

Explanation: The tendency to form +2 ionic state increase on moving down the group due to inert pair effect. Most characteristic oxidation state for lead and tin are +2,+4 respectively.

6. Answer : (a) The oxygen-oxygen bond length in ozone is identical with that of molecular oxygen

Explanation: Due to resonance the bond order in ozone is 1.5, hence O−O bond length in O₃ > O−O bond length in O₂

7. Answer : (d) Quick lime

Explanation: Quicklime (CaO) is used for drying NH₃ gas because bothare basic, do not react. On the other hand, H₂SO₄ and P₂O₅ are acidic, reacts with ammonia forming salts. CaCl₂ forms complex with ammonia.

8. Answer : (b) Lewis Acids

Explanation: The boron atom in trihaldies has only six electrons in the valence shell and hence can accept a pair of electrons in the vacant p-orbital to complete its octet. As a result, boron trihaldie act as a Lewis acids.

9. Answer : (a) Increase to 1.5 times

Explanation: 1 mole of O₃ on heating produces 1 mole of O₂ and 1 mole of [O], hence its volume increases to 1.5 times.

10. Answer : (c) Aluminum

Explanation: Aluminum is an excellent conductor of heat and electricity. Its thermal conductivity is about one-half that of copper; its electrical conductivity, about two-thirds.

11. Answer : (c) Amphoteric oxide

Explanation: Aluminium oxide is amphoteric. It has reactions as both a base and an acid. Reaction with water: Aluminum oxide is insoluble in water and does not react like sodium oxide and magnesium oxide.

12. Answer : (a) Aluminium

Explanation: Aluminium is the most abundant metal and third most abundant element in earth's crust.

13. Answer : (a) Low density

Explanation: Due to the low density of aluminium it is useful for food packaging.

14. Answer : (a) Boron

Explanation: When we mmove down the group, the IE decreases, the electropositive character, hence the metallic character also increases.

15. Answer : (a) Ga

Explanation: The m.p decreases from B to Ga , hence gallium (Ga) has least m.p. (303 K) among group of 13 element.

16. Answer : (a) of inert pair effect

Explanation: Thallium shows different (+1 and +3) oxidation states because of inert pair effect.

17. Answer : (a) B

Explanation: Boron does not react with aqueous NaOH, However, it forms borates when fused with alkalies.

18. Answer : (a) the presence of hydrogen bondstry

Explanation: In Boric acid each B atom is sp² hybridized and contains BO^-3₃ units which are held together by hydrogen bonds.

19. Answer : (a) Aluminum

Explanation: Bauxite is also known as aluminum ore and contains aluminum bearing minerals.

20. Answer : (b) 8

Explanation: In the diamond cubic unit cell, there are eight corner atoms, six face centered atoms and four more atoms inside the structure.

∴ Number of atoms present in a diamond cubic unit cell

=1 + 3 + 4 

= 8 atoms

21. Answer : (b) Pyrosilicate

Explanation: In pyrosilicates, there is only one shared oxygen, in linear chain silicates, two oxygen per tetrahedra are shared while in three-dimensional silicates, all four oxygens are shared.

22. Answer : (a) Al

Explanation: Aluminium is protected from corrosion by a layer of its own oxide Al₂O₃.

23. Answer : (a) Al

Explanation: The Hoopes process is a metallurgical process, used to obtain the aluminium metal of very high purity.

24. Answer : (c) If assertion is true but reason is false

Explanation: Al metal is rendered passive when treated with conc. HNO₃ because concentrated HNO₃ is oxidising agent and produces a protective layer of oxide on the surface.

25. Answer : (b) Ferric oxide and aluminium powder

Explanation: The powder consists of aluminum and the oxide of a metal such as iron. When ignited or heated, it gives off an enormous amount of heat as a result of the chemical combination of the aluminum with the oxygen of the oxide.

Click here to practice MCQ Questions for The p-Block Elements class 11