When a metal $X$ is treated with cold water,it gives a basic salt $Y$ with molecular formula $XOH$ (Molecular mass $= 40$) and liberates a gas $Z$ which easily catches fire. Identify $X, Y, Z$.

What is the chemical formula of bauxite?

Which of the following represents the correct order of reactivity of metals?

Which gas has the potential to become a major energy source in the future?

$(a)$ What type of ores are calcined? Illustrate by giving a suitable example.
$(b)$ In what form is the calcined ore obtained,and how can it be reduced? Give chemical equations of the reduction process involved for the example provided by you.
$(c)$ Name two metals used as reducing agents by displacing metals of lower reactivity from their compounds.

An electrolytic cell consists of
$(i)$ positively charged cathode
$(ii)$ negatively charged anode
$(iii)$ positively charged anode
$(iv)$ negatively charged cathode