Classify the following as sol,solution,or suspension:
$(i)$ Milk of magnesia
$(ii)$ Coloured gemstones
$(iii)$ Aerated drinks
$(iv)$ Emulsion paint

$(a)$ $A$ sugar syrup of mass $214.2\, g$ contains $34.2\, g$ of sugar. Calculate the concentration of sugar in the syrup.
$(b)$ What is a solution?

How are colloids different from suspensions? Identify the colloids from the following: Soda water,milk,sponge,clouds,mixture of alcohol and water,jelly.

What happens when a saturated solution is cooled?

Pragya tested the solubility of four different substances at different temperatures and collected the data as given below (results are given in the following table,as grams of substance dissolved in $100 \,g$ of water to form a saturated solution).

Substance Dissolved	$283 \,K$	$293 \,K$	$313 \,K$	$333 \,K$	$353 \,K$
Potassium nitrate	$21$	$32$	$62$	$106$	$167$
Sodium chloride	$36$	$36$	$36$	$37$	$37$
Potassium chloride	$35$	$35$	$40$	$46$	$54$
Ammonium chloride	$24$	$37$	$41$	$55$	$66$

$(a)$ Find the solubility of each salt at $293 \,K$. Which salt has the highest solubility at this temperature?
$(b)$ What is the effect of change of temperature on the solubility of a salt?

Colloidal solution appears to be homogeneous but actually it is heterogeneous. Give justification for this statement.