Draw the electron dot structure of ethyne and also draw its structural formula.

An aldehyde as well as a ketone can be represented by the same molecular formula,say $C_{3}H_{6}O$. Write their structures and name them. State the relation between the two in the language of science.

An organic compound $A$ of molecular formula $C_{2}H_{4}$ on reduction gives another compound $B$ of molecular formula $C_{2}H_{6}$. $B$ on reaction with chlorine in the presence of sunlight gives $C$ of molecular formula $C_{2}H_{5}Cl$.
$(a)$ Name the compounds $A, B$ and $C$.
$(b)$ Write the chemical equation for the conversion of $A$ to $B$ and name the type of reaction.

State whether the following statement is true or false:
Carbon, in its all allotropic forms, burns in oxygen to give nitrogen dioxide along with the release of heat and light.

Give the structural differences between saturated and unsaturated hydrocarbons with two examples each.

Write the names of the next homologues of $CH_{3}CH_{2}OH$ and $HCOOH$.