JEE Main 2013 — Chemistry Inorganic Chemistry

2013mcqmedium

In which of the following pairs of molecules/ions, both the species are not likely to exist?

Official previous-year question

Held on 7 Apr 2013 · Verified 6 Jul 2026.

Options

A
${\text{H}}_{2}^{ 2 + } \text{, } {\text{He}}_{2}$
B
${\text{H}}_{2}^{-} \text{, } {\text{He}}_{2}^{ 2 + }$
C
${\text{H}}_{2}^{+} \text{, } {\text{He}}_{2}^{ 2 - }$
D
${\text{H}}_{2}^{-} \text{, } {\text{He}}_{2}^{ 2 - }$

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Solution

(i) $\begin{matrix} {\text{H}}_{2}^{ 2 + } & \Rightarrow & \text{B} \text{.} \text{O} = 0 \\ {\text{He}}_{2} & \Rightarrow & \text{B} \text{.} \text{O} = \frac{ 2 - 2 }{ 2 } = 0 \end{matrix} }$

(ii) $\begin{matrix}{\text{H}}_{2}^{-} & \Rightarrow & \text{B}\text{.}\text{O}=\frac{2-1}{2}=0\text{.}5 \\ {\text{He}}_{2}^{2+} & \Rightarrow & \text{B}\text{.}\text{O}=1\end{matrix}$

(iii) $\begin{matrix} {\text{H}}_{2}^{+} & = & \text{B} \text{.} \text{O} = \frac{ 1 - 0 }{ 2 } = 0 \text{.} 5 \\ {\text{He}}_{2}^{ 2 - } & = & \text{B} \text{.} \text{O} = \frac{ 4 - 2 }{ 2 } = 1 \text{.} 0 \end{matrix}$

(iv) $\begin{matrix} {\text{H}}_{2}^{-} & \Rightarrow & \text{B} \text{.} \text{O} = \frac{ 2 - 1 }{ 2 } = 0 \text{.} 5 \\ {\text{He}}_{2}^{ 2 - } & \Rightarrow & \text{B} \text{.} \text{O} = \frac{ 4 - 2 }{ 2 } = 1 \text{.} 0 \end{matrix}$

As both H $_{2}$ $^{2+}$ and He $_{2}$ have zero bond order and hence do not exist.

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Options

${\text{H}}_{2}^{ 2 + } \text{, } {\text{He}}_{2}$

${\text{H}}_{2}^{-} \text{, } {\text{He}}_{2}^{ 2 + }$

${\text{H}}_{2}^{+} \text{, } {\text{He}}_{2}^{ 2 - }$

${\text{H}}_{2}^{-} \text{, } {\text{He}}_{2}^{ 2 - }$

Solution

(i) $\begin{matrix} {\text{H}}_{2}^{ 2 + } & \Rightarrow & \text{B} \text{.} \text{O} = 0 \\ {\text{He}}_{2} & \Rightarrow & \text{B} \text{.} \text{O} = \frac{ 2 - 2 }{ 2 } = 0 \end{matrix} }$

(ii) $\begin{matrix}{\text{H}}_{2}^{-} & \Rightarrow & \text{B}\text{.}\text{O}=\frac{2-1}{2}=0\text{.}5 \\ {\text{He}}_{2}^{2+} & \Rightarrow & \text{B}\text{.}\text{O}=1\end{matrix}$

As both H $_{2}$ $^{2+}$ and He $_{2}$ have zero bond order and hence do not exist.

JEE Main 2013 — Chemistry Inorganic Chemistry

Options

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Solution

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JEE Main 2013 — Chemistry Inorganic Chemistry

Options

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Solution

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JEE Main Inorganic Chemistry in other years

More JEE Main Inorganic Chemistry questions

Other Chemistry topics for JEE Main

Physical Chemistry

Organic Chemistry

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