What change will you observe if you test soap with litmus paper (red and blue)?

Draw the electron dot structures for

$(a)$ ethanoic acid.

$(b)$ $H_2S$

How would you name the following compounds ?

$(i)$ $CH _{3}- CH _{2}- Br$

$(ii)$ $\begin{matrix}
   H  \\
   |  \\
   H-C=O  \\
\end{matrix}$

$(iii)$ $\begin{matrix}
   \begin{matrix}
   H\,\,\,\,\,H\,\,\,\,\,\,\,H\,\,\,\,\,H\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \,\, \\
   |\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
\end{matrix}  \\
   H-C-C-C-C-C\equiv C-H  \\
   \,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
   H\,\,\,\,\,\,\,H\,\,\,\,\,\,\,H\,\,\,\,\,H\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
\end{matrix}$

Butanone is a four-carbon compound with the functional group

What is an homologous series ? Explain with an example.

What is hydrogenation ? What is its industrial application ?