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

The concentration of a salt solution in terms of mass by mass percentage is $20 \%$ and the mass of the solution is $550 \text{ g}$. Determine the mass of solute present in the solution. (in $\text{ g}$)

$A$ mixture of sulphur and carbon disulphide is

Classify each of the following as a physical or a chemical change. Give reasons.
$(a)$ Drying of a shirt in the sun.
$(b)$ Rising of hot air over a radiator.
$(c)$ Burning of kerosene in a lantern.
$(d)$ Change in the colour of black tea on adding lemon juice to it.
$(e)$ Churning of milk cream to get butter.

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

Sidak took $50\, mL$ of water in two beakers at room temperature and added sodium chloride to one beaker while sugar to the other,until no more solute could be dissolved. Then she heated the contents of the beakers and added more solutes in them.
$(a)$ Will the amount of salt and sugar that can be dissolved in water at a given temperature be the same?
$(b)$ What would you expect to happen if she cools the contents of the beakers? Justify your answer.