In which solution will thymol blue indicator appear blue?
(1) 0.1 M CH3COOH (3) 0.1 M HCl
(2) 0.1 M KOH (4) 0.1 M H2SO4



Answer :

In 0.1 M KOH, thymol blue indicator would appear blue. 

Answer: (2) 0.1 M KOH

Explanation:

Thymol blue is an universal indicator. Thymol blue has a blue color when in basic conditions (pH > 7), a green color in neutral conditions (pH =7), and a yellow color in acidic conditions (pH < 7).

pH or pOH is the measure of acidity or alkalinity of a solution.  pH is calculated by taking negative logarithm of hydrogen ion concentration.

0.1 M [tex]CH_3COOH[/tex] ,  0.1 M [tex]HCl[/tex]  and  0.1 M [tex]H_2SO4[/tex] are all acidic in nature.

Thus thymol blue will appear blue in basic 0.1 M KOH.