The p-Block Elements Questions and Answers Part-4

1. Although Al has a high oxidation potential it resists corrosion because of the formation of a tough, protective coat of
a) \[Al\left(NO_{3}\right)_{3}\]
b) AlN
c) \[Al_{2}O_{3}\]
d) \[Al_{2}\left(CO_{3}\right)_{3}\]

Answer: c
Explanation: \[Al_{2}O_{3}\]

2. \[AlCl_{3}\] on hydrolysis gives
a) \[Al_{2}O_{3}.H_{2}O\]
b) \[Al_{2}O_{3}\]
c) \[Al\left(OH_{3}\right)\]
d) \[AlCl_{3}.6H_{2}O\]

Answer: c
Explanation: \[AlCl_{3}\]  on hydrolysis gives \[Al\left(OH_{3}\right)\]

3. Action of caustic soda on aluminium hydroxide gives a compound having formula
a) \[Al_{2}\left(OH\right)_{4}\]
b) \[Na_{2}Al\left(OH\right)_{4}\]
c) \[NaAlO_{2}\]
d) \[Na_{3}AlO_{3}\]

Answer: c
Explanation:
q33

4. \[Al\left(OH\right)_{3}\]  is
a) acidic
b) basic
c) amphoteric
d) neither acidic nor basic

Answer: c
Explanation: \[Al\left(OH\right)_{3}\]  is amphoteric

5. A lake can be obtained by making a mixture of a coloured dye with
a) \[NH_{4}OH\]
b) \[Ba\left(OH\right)_{2}\]
c) \[Al\left(OH\right)_{3}\]
d) NaOH

Answer: c
Explanation: \[Al\left(OH\right)_{3}\]

6. \[AlCl_{3}\]  is
a) anhydrous and covalent
b) anhydrous and ionic
c) covalent and basic
d) coordinate and acidic

Answer: a
Explanation: \[AlCl_{3}\] is anhydrous and covalent

7. Anhydrous \[AlCl_{3}\]  is prepared from
a) conc. HCl and Al metal
b) aluminium and \[Cl_{2}\]
c) dry HCl gas + heated Al metal
d) dil. HCl and Al metal

Answer: c
Explanation:
q37

8. Aluminium chloride is a/an
a) Bronsted - Lowry acid
b) Arrhenius acid
c) Lewis acid
d) Lewis base

Answer: c
Explanation: Aluminium chloride is a/an lewis acid

9. Which member of group 13 does not exhibit the group valency in its compounds ?
a) Boron
b) Aluminium
c) Gallium
d) Thallium

Answer: c
Explanation: Gallium

10. The highly toxic element of group 13 is
a) Al
b) B
c) Ga
d) Tl

Answer: d
Explanation: The highly toxic element of group 13 is Tl