Bessemerisation is carried out for

Percentage of silver in German silver is (in $\%$)

Which of the following alloys contains $Sn$ metal?

To obtain steel entirely free from sulphur and phosphorus,the process used is

Match the following:

List-$I$	List-$II$
$A. Al_2O_3 + 2NaOH + 3H_2O \rightarrow 2Na[Al(OH)_4]$	$I. \text{Roasting}$
$B. Ni(CO)_4 \xrightarrow{230^{\circ}C} Ni + 4CO$	$II. \text{Calcination}$
$C. Fe_2O_3 \cdot 3H_2O \xrightarrow{\Delta} Fe_2O_3 + 3H_2O$	$III. \text{Vapour phase refining}$
$D. 2PbS + 3O_2 \rightarrow 2PbO + 2SO_2$	$IV. \text{Electrolysis}$
	$V. \text{Leaching}$

The correct answer is:

Explain the following:
$(a)$ $CO_2$ is a better reducing agent below $710 \ K$ whereas $CO$ is a better reducing agent above $710 \ K$.
$(b)$ Generally,sulphide ores are converted into oxides before reduction.
$(c)$ Silica $(SiO_2)$ is added to the sulphide ore of copper in the reverberatory furnace.
$(d)$ Carbon and hydrogen are not used as reducing agents at high temperatures for certain metals.
$(e)$ Vapour phase refining method is used for the purification of $Ti$.