Chemical Bonding - Result Question 74
####50. Match each of the diatomic molecules in Column I with its property/properties in Column II.
(2009)
| Column I | ColumnII | ||
|---|---|---|---|
| A. | $B _2$ | p. | Paramagnetic |
| B. | $N _2$ | q. | Undergoes oxidation |
| C. | $O _2^{-}$ | r. | Undergoes reduction |
| D. | $O _2$ | s. | Bond order $\geq 2$ |
| t. | Mixing of ’ $s$ ’ and ’ $p$ ’ orbitals |
Codes
| A | B | C | D | |
|---|---|---|---|---|
| (a) | q, r, s | p, r, t, s | q, r, t | p, q, t |
| (b) | p, q, r, t | q, r, s, t | p, q, r, t | p, r, s, t |
| (c) | q, r, s, t | p, q,r | r, s, t | p, q, r, t |
| (d) | p, q, s, t | p, q, s | p, t | q, r, t |
Fill in the Blanks
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Answer:
Correct Answer: 50. (b) $A \rightarrow p, q, r, t ; B \rightarrow q, r, s, t ; C \rightarrow p, q, r, t ; D \rightarrow p, r, s, t$
Solution:
- (A) $B _2: \sigma 1 s^{2} \stackrel{}{\sigma} 1 s^{2} \sigma 2 s^{2} \stackrel{}{\sigma} 2 s^{2}\left|\begin{array}{l}\pi 2 p _y^{1} \ \pi 2 p _z^{1}\end{array}\right|$ paramagnetic.
Bond order $=\frac{6-4}{2}=1$
Bond is formed by mixing of $s$ and $p$ orbitals.
$B _2$ undergoes both oxidation and reduction as
$$ \begin{aligned} & B _2+O _2 \xrightarrow{\text { Heat }} B _2 O _3 \quad \text { (Oxidation) } \ & B _2+H _2 \longrightarrow B _2 H _6 \text { (Reduction) } \end{aligned} $$
(B) $N _2: \sigma 1 s^{2}{ }^{} \sigma 1 s^{2} \sigma 2 s^{2}{ }^{} \sigma 2 s^{2} \sigma 2 p _x^{2}\left|\begin{array}{l}\pi 2 p _y^{2} \ 10-4\end{array}\right|$ diamagnetic.
Bond order $=\frac{10-4}{2}=3>2$
$N _2$ undergoes both oxidation and reduction as
$$ \begin{aligned} N _2+O _2 & \stackrel{\Delta}{\longrightarrow} NO \ N _2+3 H _2 & \stackrel{\text { Catalyst }}{\longrightarrow} NH _3 \end{aligned} $$
In $N _2$, bonds are formed by mixing of $s$ and $p$ orbitals.
(C) $O _2^{-}: \left.\sigma 1 s^{2} \stackrel{}{\sigma} 1 s^{2} \sigma 2 s^{2} \stackrel{}{\sigma} 2 s^{2} \sigma 2 p _x^{2}\left|\begin{array}{ll}\pi 2 p _y^{2} \ \pi 2 p _z^{2}\end{array}\right| \begin{aligned} & * \ & \pi 2 p _y^{2}\end{aligned} \right\rvert, \stackrel{}{} 2 p _x^{0}$
Paramagnetic with bond order $=1.5 . O _2^{-}$undergoes both oxidation and reduction and bond involves mixing of $s$ and $p$-orbitals.
(D) $O _2: \sigma 1 s^{2} \stackrel{}{\sigma} 1 s^{2} \sigma 2 s^{2} \stackrel{}{\sigma} 2 s^{2} \sigma 2 p _x^{2}\left|\begin{array}{l}\pi 2 p _y^{2} \ \pi 2 p _z^{2}\end{array}\right| \begin{aligned} & \pi \ & \pi 2 p _z^{1}\end{aligned}|\stackrel{}{1}| \stackrel{}{\sigma} 2 p _x^{0}$
Paramagnetic with bond order $=2$.
$O _2$ undergoes reduction and the bond involves mixing of $s$ and $p$-orbitals.
