The first member of the alkyne homologous series is:

Complete the following chemical reactions and write the chemical name of the products obtained.
$(i)$ $CH_{2}=CH_{2} + H_{2}O \longrightarrow$
$(ii)$ $CH_{3}COOH + NaOH \longrightarrow$
$(iii)$ $CH_{3}CH_{2}OH \xrightarrow{H_{2}SO_{4}} $
$(iv)$ $HCOOH + Na \longrightarrow$
$(v)$ $C_{2}H_{5}OH \xrightarrow{\text{Alk. } KMnO_{4}} $

Which of the following is the correct representation of the electron dot structure of nitrogen $(N_2)$?

On dropping a small piece of sodium in a test tube containing carbon compound $X$ with molecular formula $C_{2}H_{6}O$,a brisk effervescence is observed and a gas $Y$ is produced. On bringing a burning splinter at the mouth of the test tube,the gas evolved burns with a pop sound. Identify $X$ and $Y$. Also,write the chemical equation for the reaction. Write the name and structure of the product formed when you heat $X$ with excess concentrated sulphuric acid.

Which of the following compounds has a sweet,fruity smell?

State the valency of each carbon atom in $(i)$ an alkane and $(ii)$ an alkyne.