Question

4) Which indicator, when added to a solution, changes color from yellow to blue as the pH of the
solution is changed from 5.5 to 8.0?
a bromcresol green
b) Litmus
c) bromthymol blue
d) methyl orange

Answer 1

Answer:

c) bromthymol blue

Explanation:

An acidic solution has a pH value less than 7, while the pH is 7 for a neutral solution and grater than 7 for a basic solution.

Bromothymol blue is a pH indicator which is yellow in color when placed in an acid (pH under 7), the color is green in a neutral solution (pH of 7) and blue in an basic solution (pH over 7).

If bromthymol blue is added to a solution with an initial pH of 5.5 (acidic), the color would be yellow and as the pH changes to 8 (basic), the color changes to blue.