Which of the following alloys contains a non-metal?

Tempered steel is

$A$ white solid '$A$' on heating produces a gas that turns lime water milky,and the remaining solid residue is yellow when hot but turns white on cooling. The solid '$A$' is:

Which of the following thermal stability orders is correct?

$A$ red coloured mixed oxide $(X)$ on treatment with conc. $HNO_3$ gives a compound $(Y).$ $(Y)$ with $HCl$ produces a chloride compound $(Z)$ which can also be produced by treating $(X)$ with conc. $HCl.$ Compounds $(X),$ $(Y),$ and $(Z)$ will be

Which of the anhydrous salts,when it comes in contact with water,turns blue?