How is scum formed?

$A$ carboxylic acid (molecular formula $C_{2}H_{4}O_{2}$) reacts with an alcohol in the presence of an acid catalyst to form a compound $'X'$. The alcohol on oxidation with alkaline $KMnO_{4}$ followed by acidification gives the same carboxylic acid $C_{2}H_{4}O_{2}$. Write the name and structure of $(i)$ carboxylic acid,$(ii)$ alcohol,and $(iii)$ the compound $'X'$.

Name an element,other than carbon,which exhibits the property of catenation up to seven or eight atoms. Are these compounds stable?

Write the chemical equations for the reactions of ethanoic acid with the following:
$(a)$ Sodium
$(b)$ Sodium hydroxide
$(c)$ Ethanol
Also,write the name of one main product for each reaction.

Draw the structure of the simplest ketone.

What is produced when ethanol reacts with sodium metal?