Question

Which of the following are the correct observations about acetic acid?
(A) It turns blue litmus red and smells like vinegar
(B) It turns blue litmus red and smells like burning sulphur
(C) It turns red litmus blue and smells like vinegar
(D) It turns red litmus blue and has a fruity smell

Answer 1

Hint : The IUPAC name of acetic acid is ethanoic acid having the molecular formula $C{{H}_{3}}COOH$ . It is prepared industrially by oxidation of acetaldehyde and oxidation of ethanol.

Complete Step By Step Answer:
Acetic acid or ethanoic acid is colourless liquid. It is an organic compound having two carbon atoms.
The formula of acetic acid is $C{{H}_{3}}COOH$ or can be written as $C{{H}_{3}}C{{O}_{2}}H$ or ${{C}_{2}}{{H}_{4}}{{O}_{2}}$ or $H{{C}_{2}}{{H}_{3}}{{O}_{2}}$ .
There are many different tools and techniques to measure pH of a solution. Litmus paper is one of those. It is a piece of paper that tells us about the acidity or basicity of a solution by colour change. It is one of the basic techniques and simple but lacks efficiency and precision.
There are two colours in a litmus paper red and blue. If the colour changes from red to blue then the solution is basic and if it changes from blue to red it is acidic.
Other techniques can be pH meter which is more precise than pH paper which tells us about the exact pH of the solution.
Acetic acid will turn blue litmus red and smells like vinegar.

Note :
Since acetic acid is an acid so it is quite obvious that it will turn blue litmus red. Also it smells like vinegar since vinegar is $3-9$ acetic acid by volume due to which vinegar is the main component of acetic acid.