The p-Block Elements Questions and Answers Part-2

1. \[B_{2}O_{3}\] is
a) acidic
b) basic
c) amphoteric
d) None of these

Answer: a
Explanation: \[B_{2}O_{3}\] is acidic

2. Boric acid is polymeric due to
a) its acidic nature
b) the presence of hydrogen bonds
c) its monobasic nature
d) its geometry

Answer: b
Explanation:
q123

3. \[B\left(OH\right)_{3}\]   is
a) monobasic acid
b) dibasic acid
c) tribasic acid
d) triacidic base

Answer: a
Explanation: \[B\left(OH\right)_{3}\]  is monobasic acid

4. Which of the following hydroxide is acidic ?
a) \[Al\left(OH\right)_{3}\]
b) \[Ca\left(OH\right)_{3}\]
c) \[Tl\left(OH\right)_{3}\]
d) \[B\left(OH\right)_{3}\]

Answer: d
Explanation:
q14

5. \[BF_{3}\] acts as an acid according to the concept of
a) Lewis
b) Bronsted
c) Arrhenius
d) None of these

Answer: a
Explanation: Since BF3 is an electron deficient molecule (according to lewis concept)

6. Which of the following is electron deficient ?
a) \[NH_{3}\]
b) \[BCl_{3}\]
c) \[PCl_{3}\]
d) None of these

Answer: b
Explanation: \[BCl_{3}\]

7. \[NH_{3}\] and \[BF_{3}\] form an adduct readily because they form
a) a coordinate bond
b) a hydrogen bond
c) an ionic bond
d) a covalent bond

Answer: a
Explanation: \[NH_{3}\] and \[BF_{3}\] form an adduct readily because they form a coordinate bond

8. \[BF_{3}\] is used as a catalyst in several industrial processes due to its
a) strong reducing nature
b) weak reducing action
c) strong Lewis acid nature
d) weak Lewis acid character

Answer: d
Explanation: \[BF_{3}\] is used as a catalyst in several industrial processes due to its weak Lewis acid character

9. Among the halides of the elements of group 13 the one which is most acidic is
a) \[BF_{3}\]
b) \[AlCl_{3}\]
c) \[BCl_{3}\]
d) \[BBr_{3}\]

Answer: d
Explanation: \[BBr_{3}\]

10. In diborane
a) 4–bridged hydrogens and two terminal hydrogens are present
b) 2– bridged hydrogens and four terminal hydrogens are present
c) 3–bridged and three terminal hydrogens are present
d) None of these

Answer: b
Explanation: 2– bridged hydrogens and four terminal hydrogens are present