Class 12 Chemistry Chapter 7 p Block Elements MCQs | Class 12 Chemistry Chapter 7 p Block Elements Multiple Choice Questions (MCQs) and Answers

Questions
1 In the presence of KF, AlF3 is soluble in HF. Find the complex formed

A K3[AlF6]
B AlH3
C K[AlF3H]
D K3[AlF3H3]

Answer:K3[AlF6]
2 S-S bond is present in which of the ion pairs

A S2O72-, S2O32-
B S4O62-, S2O72-
C S2O72-, S2O82-
D S4O62-, S2O32-

Answer:S4O62-, S2O32-
3 Which is the correct order of decreasing bond dissociation enthalpy?

A F2 > Cl2 > Br2 > I2
B I2 > Br2 > Cl2 > F2
C Cl2 > Br2 > F2 > I2
D Br2 > I2 > F2 > Cl2

Answer: Br2 > I2 > F2 > Cl2
4 Oxygen is not released on heating which of the compounds?

A (NH4)2Cr2O7
B K2Cr2O7
C Zn(ClO3)2
D KClO3

Answer:(NH4)2Cr2O7
5 Which of the species has a permanent dipole moment?

A SF4
B SiF4
C BF3
D XeF4

Answer: SF4
6 Which of the statement is incorrect for XeO4 ?
A four pπœ‹-dπœ‹ bonds are present
B four sp3 – p 𝜎 bonds are present
C It has a tetrahedral shape
D It has a square planar shape

Answer:It has a square planar shape
7 P4O10 has ______ bridging O atoms
A 4
B 5
C 6
D 2

Answer:6
8 Find the amphoteric oxide

A CaO2
B CO2
C SnO2
D SiO2

Answer:SnO2
9 Graphite has a structural similarity with

A B2H6
B B4C
C B
D BN

Answer:BN
10 Which is the correct order of decreasing acidity of lewis acids?

A BBr3 > BCl3 > BF3
B BF3 > BCl3 > BBr3
C BCl3 > BF3 > BBr3
D BBr3 > BF3 > BCl3

Answer:BBr3 > BCl3 > BF3
11 Boron form covalent Compound due to
A Higher ionisation enthalpy
B Lower ionisation enthalpy
C Small size
D Both (a) and (c)

Answer:Both (a) and (c)
12 In diborane the Two H-B-H angles are nearly
A 60° , 120°
B 95° ,120° 
C 95° ,150° 
D 120° ,180°

Answer: 95° ,120° 
13 The stability of +1 oxidation state increases in the sequence
A Al< Ga< In< Tl
B Tl< In< Ga< Al
C In< Tl< Ga< Al
D Ga< In< Al< Tl

Answer: Al< Ga< In< Tl
14 Which of the following is most acidic
A Na2O
B Mgo
C Al2O3
D Cao

Answer: Al2O3
15 Cohen Orthoboric acid (H3BO3) is strongly heated, the residue is
A Meta boric acid
B Boron
C Al2O3, 2H2O
D None of above

Answer:Meta boric acid
16 Bauxite has the composition
A Al2O3
B Al2O3, H2O
C Al2O3 • 2H2O
D All the given

Answer: Al2O3 • 2H2O
17 Which one of the following is correct statement
A The hydroxide of aluminium is more acidic than that of boron
B The hydroxide of boron is basic, while that of aluminium is amphoteric
C The hydroxide of boron is acidic, while that of aluminium is amphoteric
D The hydroxide of boron & aluminium are amphoteric

Answer: The hydroxide of boron is acidic, while that of aluminium is amphoteric
18 AlCl3 is
A Anhydrous & covalent
B Anhydrous & ionic
C Covalent & basic
D Coordinate & acidic

Answer:Anhydrous & covalent
19 Aluminium (III) chloride forms a dimer because
A Higher coordination number can be achieved by aluminium
B Aluminium has high ionization energy
C Aluminium belongs to III group
D It cannot form a trimer

Answer: Higher coordination number can be achieved by aluminium
20 Aluminium has a great affinity for oxygen & it’s oxidation is an exothermic process. This fact is used in
A Preparing thin foils of aluminium
B Making utensils
C Preparing duralumin alloy
D Thermite welding

Answer: Thermite welding

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