Compound A has three carbon atoms, which burns with non-sooty flame. Predict what is A? Write its electron dot structure.

Soaps are prepared by treating the esters of fatty acid with alkali. Sometimes common salt is also added to it. Why is common salt added during this process?

Scientists detect the presence of sodium bicarbonate in a water sample. Can this water be used for washing clothes with soap? Justify your answer.

Two non-metals A and B combine with each other by sharing of electron to form compound C.

(i) What is the nature of compound C?

(ii) Will it dissolve in water or organic solvents? Give reason for your answer.

Account for the following.

(i) Sunlight is necessary for the substitution reactions of saturated hydrocarbons.

(ii) Ethyne burns with a yellow flame and lots of black smoke.