Which of the following ores is in the form of carbonate?

Of the three metals $X, Y$ and $Z$,$X$ reacts with cold water,$Y$ with hot water,and $Z$ with steam only. Identify $X, Y$ and $Z$ and also arrange them in the order of increasing reactivity.

$(a)$ List two differences between calcination and roasting in tabular form.
$(b)$ Which method will you use to reduce the following? Explain by giving a suitable example.
$(i)$ Oxides of less reactive metals.
$(ii)$ Oxides of moderately reactive metals.
$(iii)$ Oxides of highly reactive metals.

Which gas is used in the process of converting vegetable oils into vegetable ghee?

What is the name of the apparatus used for the electrolysis of pure water?

During the refining of copper by electrolysis,copper deposits at the $....$.