Bronze is a mixture of . . . . . . metals.

Which of the following metals is present in Brass,Bronze,and German silver?

Spiegeleisen is an alloy of

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 $Ti$.

Metals are extracted by other methods through the formation of complexes. The complexes formed in these methods are: $I$: Cyanide process,$II$: Mond process,$III$: Photographic fixing process.

Addition of high proportions of manganese makes steel useful in making rails of rail-roads because manganese