What is the percentage of sulfur used in vulcanized rubber for battery casings (in $\%$)?

Which method/process is used to prepare sulphuric acid?

$(i)$ Name a metal which does not stick to glass.
$(ii)$ Name the metal which is commonly used in thermite welding.
$(iii)$ What is the nature of zinc oxide?

Which alloy is used for making statues and medals?

Give reasons for the following:
$(i)$ Alloys are used in electrical heating devices rather than pure metals.
$(ii)$ Gold ornaments look new even after several years of use.
$(iii)$ An iron grill should be painted frequently.

Which one of the following figures correctly describes the process of electrolytic refining?