Stainless steel is an alloy of

Which of the following pairs is incorrectly matched?

How is cement clinker obtained?

Flux is used to remove ...... .

List-$I$ shows reactions involved in the metallurgy of $Pb$ (lead) and List-$II$ shows the names of the processes. Match List-$I$ with List-$II$ and select the correct code for your answer.

List-$I$	List-$II$
$(P) \ PbS + 2PbO \xrightarrow{\Delta} 3Pb + SO_2 \uparrow$	$(1) \ \text{Smelting}$
$(Q) \ PbS + \frac{3}{2}O_2 \xrightarrow{\Delta} PbO + SO_2 \uparrow$	$(2) \ \text{Self reduction}$
$(R) \ PbCO_3 \xrightarrow{\Delta} PbO + CO_2 \uparrow$	$(3) \ \text{Calcination}$
$(S) \ PbO + C \xrightarrow{\Delta} Pb + CO \uparrow$	$(4) \ \text{Roasting}$

Identify the correct statements from the following:
$I$. Brass is an alloy of copper and nickel
$II$. Bronze is an alloy of copper and zinc
$III$. German silver is an alloy of copper,zinc and nickel
$IV$. Brass is an alloy of copper and zinc