MCQ
The Lanthanoid contraction refers to:
- ✓Vlence electrons of the Lanthanide series.
- BIonic radius of the series.
- CThe density of the series.
- DNuclear mass of the series.
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(Where the constant $B$ is positive)
Statement $(I)$ : Fusion of $\mathrm{MnO}_2$ with $\mathrm{KOH}$ and an oxidising agent gives dark green $\mathrm{K}_2 \mathrm{MnO}_4$.
Statement $(II)$ : Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion.
In the light of the above statements, choose the correct answer from the options given below.
$\left[\right.$ Given : $K _{ sp }( AgBr )=4.9 \times 10^{-13}$ at $298 K$
$\lambda_{ Ag ^{+}}^0=6 \times 10^{-3} Sm ^2\,mol ^{-1}$
$\lambda_{ Br ^{-}}^0=8 \times 10^{-3} Sm ^2\,mol ^{-1}$
$\left.\lambda_{ NO _3^{-}}^0=7 \times 10^{-3} Sm ^2\,mol ^{-1}\right]$
| List $I$ Name of reaction | List $II$ Reagent used |
| $A$ Hell-Volhard-Zelinsky reaction | $I$ $NaOH + I _2$ |
| $B$ Iodoform reaction | $II$ (i) $CrO _2 Cl _2, CS _2$ (ii)$H _2 O$ |
| $C$ Etard reaction | $III$ (i) $Br _2 /$ red phosphorus (ii) $H _2 O$ |
| $D$ Gatterman-Koch reaction | $IV$ $CO , HCl$, anhyd.$AlCl_3$ |
Choose the correct answer from the options given below: