How can we obtain pure copper sulphate from an impure sample?

Which of the following is an aqueous solution?

Write your observations when the following processes take place:
$(a)$ An aqueous solution of sugar is heated to dryness.
$(b)$ $A$ saturated solution of potassium chloride prepared at $60^\circ C$ is allowed to cool at room temperature.
$(c)$ $A$ mixture of iron filings and sulphur powder is heated strongly.
$(d)$ $A$ beam of light is passed through a colloidal solution.
$(e)$ $Dil. HCl$ is added to the mixture of iron and sulphur.

Two chemical species $X$ and $Y$ combine together to form a product $P$ which contains both $X$ and $Y$.
$X + Y \to P$
$X$ and $Y$ cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species $X$,$Y$ and $P$ are correct?
$(i)$ $P$ is a compound
$(ii)$ $X$ and $Y$ are compounds
$(iii)$ $X$ and $Y$ are elements
$(iv)$ $P$ has a fixed composition

Which of the following materials fall in the category of a "pure substance"?

How are mixtures different from compounds?