4
MCQ (Single Correct Answer)
Hydrogen bonds are formed in many compounds e.g., $\mathrm{H}_2 \mathrm{O}, \mathrm{HF}, \mathrm{NH}_3$. The boiling point of such compounds depends to a extent on the strength of hydrogen bond and the number of hydrogen bonds. The correct decreasing order of the boiling points above compounds is
A
$\mathrm{HF}>\mathrm{H}_2 \mathrm{O}>\mathrm{NH}_3$
B
$\mathrm{H}_2 \mathrm{O}>\mathrm{HF}>\mathrm{NH}_3$
C
$\mathrm{NH}_3>\mathrm{HF}>\mathrm{H}_2 \mathrm{O}$
D
$\mathrm{NH}_3>\mathrm{H}_2 \mathrm{O}>\mathrm{HF}$
5
MCQ (Single Correct Answer)
In $\mathrm{PO}_4^{3-}$ ion the formal charge on the oxygen atom of $\mathrm{P}-0$ bond is
A
+1
B
$$-$$1
C
$$-$$0.75
D
+0.75
6
MCQ (Single Correct Answer)
In $\mathrm{NO}_3^{-}$ion, the number of bond pairs and lone pairs of electrons on nitrogen atom are
A
2, 2
B
3, 1
C
1, 3
D
4, 0
7
MCQ (Single Correct Answer)
Which of the following species has tetrahedral geometry?
A
$\mathrm{BH}_4^{-}$
B
$\mathrm{NH}_2^{-}$
C
$\mathrm{CO}_3^{2-}$
D
$\mathrm{H}_3 \mathrm{O}^{+}$
8
MCQ (Single Correct Answer)
Number of $$\pi$$ bonds and $$\sigma$$ bonds in the following structure is
A
6, 19
B
4, 20
C
5, 19
D
5, 20