Question

Among statements (a) - (d), the correct ones are
(a) Lime stone is decomposed to $CaO$ during the extraction of iron from its oxides.
(b) In the extraction of silver, silver is extracted as an anionic complex.
(c) Nickel is purified by Mond's process.
(d) $Zr$ and $Ti$ are purified by Van Arkel method.

• A. (b), (c) and (d) only
• B. (c) and (d) only
• C. (a), (c) and (d) only
• D. (a), (b), (c) and (d)

Answer 1

The correct option is D (a), (b), (c) and (d)

$CaC{O}_3\stackrel{500-800K}{\to }CaO+C{O}_2$

In extraction of silver, silver is extracted as an anionic complex $\left[Ag\right(CN{)}_2{]}^{-}$.

Mond's process is used for purification of $Ni$
Vapour Phase Refining
Step 1:
Ni is heated in stream of $CO$ to form nickel tetracarbonyl
$Ni+4CO\stackrel{330-350K}{\to }\underset{\text{Volatile}}{Ni(CO{)}_4}$
Step2:
Volatile compound is subjected to higher temperature
$Ni(CO{)}_4\stackrel{450-470K}{\to }\underset{\text{Pure metal}}{Ni}+4CO$


$TiandZr$ metal is refined by the Van-Arkel method. Metal is converted (by heating with little iodine) to volatile (covalent) tetraiodide which is then decomposed ( by electrically heating above 1800 K with tungsten filament ) to pure metal which is deposited on a tungsten filament.
Reactions:
$Zr+2I_2\to \underset{\text{More Covalent}\text{Volatilises}}{Zr{I}_2}$
$Zr{I}_2\to \underset{\text{Pure Metal}}{Zr}+2I_2$
All the statements are correct