What is the effect of temperature on the solubility of solids in liquids?

Write the role of the following in a water purification system:
$(a)$ Sedimentation tank
$(b)$ Loading tank
$(c)$ Chlorination tank

$(a)$ Write any three points of differences between homogeneous and heterogeneous mixtures.
$(b)$ Give two reasons for supporting that water is a compound and not a mixture.

State any one difference between pure and impure substances.

Three students $A, B$ and $C$ prepared mixtures using chalk powder,common salt and milk respectively in water. Whose mixture
$(i)$ would not leave residue on filter paper after filtration?
$(ii)$ would show Tyndall effect?
$(iii)$ would give transparent/clear solution?
$(iv)$ would settle down at the bottom when left undisturbed?
$(v)$ could be filtered by filter paper?

Name the appropriate methods to separate the following:
$(i)$ Nitrogen from air
$(ii)$ Dye from blue ink
$(iii)$ Butter cream from milk
$(iv)$ Ammonium chloride from common salt