Question

Four students observed the colour and odour of acetic acid and its reaction with sodium hydrogen carbonate. They tabulated their observations as given below.
Student
Colour of acetic acid
Odour of acetic acid
Action with sodium hydrogen carbonate
A
B
C
D
blue
colourless
light green
light brown
fruity
smell of vinegar
odourless
rotten egg
gas evolves without bubbles
effervescence
gas evolves without bubbles
effervescence
The correct set of observation is that of student:
(1) A
(2) B
(3) C
(4) D

Answer 1

Explanation:

The correct set of observation is that of student:

(1) A

(2) B✔️

(3) C

(4) D

Answer 2

Student B has the correct observation: Colourless, smell of vinegar and effervescence.

Explanation:

Ethanoic acid or acetic acid is colourless and smells like vinegar. It is water soluble. Acetic acid is a weak acid as it does not dissociate much in solution. There will be more whole molecules of acetic acid than separate acetate and hydrogen ions. It turns blue litmus paper red. With Sodium hydrogen carbonate, you can observe a brisk effervescence due to the escape of carbon dioxide.