Which of the following functional groups is present in aldehyde compounds?

What is used to prepare white lead?

What is the common name of $Methanal$?

Write the name and general formula of a chain of hydrocarbons in which an addition reaction with hydrogen is possible. State the essential condition for an addition reaction. Stating this condition,write a chemical equation giving the name of the reactant and the product of the reaction.

$A$ hydrocarbon,$C_{2}H_{4}$,decolorizes bromine water.
$(i)$ Name the hydrocarbon.
$(ii)$ Mention the family to which it belongs.
$(iii)$ Write the chemical equation of the reaction of this hydrocarbon with hydrogen.

Alkynes may be represented by the general formula: