MCQ
Which of the following is paramagnetic ?
- ✓$O_2[AsF_6]$
- B$Al_2O_3$
- C$C_2$
- D$Be_2$
$\mathrm{C}_{2}=\sigma 1 \mathrm{s}^{2}, \sigma^{*} 1 \mathrm{s}^{2}, \sigma 2 \mathrm{s}^{2}, \sigma^{*} 2 \mathrm{s}^{2}, \pi 2 \mathrm{p}_{\mathrm{x}}^{2}, \pi 2 \mathrm{p}_{\mathrm{y}}^{2}$
Number unpaired electrons.
$\mathrm{Be}_{2}=\sigma 1 \mathrm{s}^{2}, \sigma^{*} 1 \mathrm{s}^{2}, \sigma 2 \mathrm{s}^{2}, \sigma^{*} 2 \mathrm{s}^{2}$
No unpaired electrons.
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$2NO + Br \to 2NOBr$ is
$NO + Br_2 \rightleftharpoons NOBr_2$ (Fast)
$NOBr_2 + NO \to 2NOBr$ (Slow)
The rate law expression is
$\mathrm{MnO}_2+\mathrm{KOH}+\mathrm{O}_2 \rightarrow \mathrm{A}+\mathrm{H}_2 \mathrm{O} .$
Product ' $A$ ' in neutral or acidic medium disproportionate to give products ' $\mathrm{B}$ ' and ' $\mathrm{C}$ ' along with water. The sum of spin-only magnetic moment values of $B$ and $C$ is . . . . . .$BM$. (nearest integer)
(Given atomic number of $\mathrm{Mn}$ is $25$ )
[At. No.: $Cr= 24,\,Mn= 25, \,Fe= 26, \,Co= 27$]