What is the reaction to form soap known as?

An organic compound burns with a sooty flame. Is it a saturated or an unsaturated compound?

$A$ 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 $'X'$.

How would you bring about the following conversions? Name the process and write the reaction involved.
$(a)$ Ethanol to ethene.
$(b)$ Propanol to propanoic acid.
Write the reactions.

In the presence of which enzyme does the fermentation of glucose or fructose occur to produce ethanol and carbon dioxide?

The structural formula of benzene is: