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?

$(a)$ What is the effect of temperature on the solubility of a solid in a liquid?
$(b)$ Why is it possible to distinguish the particles of solute from those of solvent in a suspension?

$(a)$ Differentiate between a mixture and a compound.
$(b)$ You are provided with a mixture containing sand,iron filings,naphthalene,and sodium chloride. Describe the procedures you would use to separate these constituents from the mixture.

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.

Which of the following statements are true for pure substances?
$(i)$ Pure substances contain only one kind of particles.
$(ii)$ Pure substances may be compounds or mixtures.
$(iii)$ Pure substances have the same composition throughout.
$(iv)$ Pure substances can be exemplified by all elements other than nickel.

What would you observe when:
$(a)$ a saturated solution of potassium chloride prepared at $60^{\circ} C$ is allowed to cool at room temperature?
$(b)$ an aqueous sugar solution is heated to dryness?
$(c)$ a mixture of iron filings and sulphur powder is heated strongly?