p- Block Elements XII

p- Block Elements
Class:XII / Unit:7

1. Which is the strongest acid in the following?

H₂SO₄
H₂SO₃
HClO₃
HClO₄

2. Which of the following does not give oxygen on heating?

K₂Cr₂O₇
(NH₄)₂Cr₂O₇
KClO₃
Zn(ClO₃)₂

3. XeF2 is isostructural with

BaCl₂
TeF₂
ICl₂^–
SbCl₃

4. The pair of species that has the same bond order in the following is:

NO^–, CN^–
O₂, N₂
CO, NO⁺
O₂, B₂

5. Which one of the following is an amphoteric oxide?

Na₂O
B₂O₃
ZnO
SO₂

6. Which blue liquid is obtained on reacting equimolar amounts of two gases at -30°C

N₂O₅
N₂O₃
N₂O₄
N₂O

7. Which of the following is arranged in the increasing order of enthalpy of vaporisation?

PH₃, AsH₃, NH₃
AsH₃, PH₃, NH₃
NH₃, PH₃, AsH₃
NH₃, AsH₃, PH₃

8. Molecules of a noble gas do not possess vibrational energy because a noble gas

is chemically inert
is monoatomic
is diamagnetic
has completely filled shells

9. Which of the following statements is true?

HNO₃ is a stronger acid than HNO₂
HClO₄ is a weaker acid than HClO₃
In aqueous medium HF is a stronger acid than HCl
H₃PO₃ is a stronger acid than H₂SO₃

10. The decreasing values of bond angles from NH3 (106°) to SbH3 (101°) down group-15 of the periodic table is due to

increasing p-orbital character in sp³
decreasing lp-bp repulsion
increasing bp-bp repulsion
decreasing electronegativity