Question

Which statement below best describes how the chemical indicator bromthymol blue (BTB) works? BTB responds to the presence of carbon dioxide by changing color. BTB is added to aquarium water to keep it blue. BTB will respond to the presence of oxygen by changing color.

Answer 1

BTB respond to the presence of carbondioxide by changing color.

Answer 2

BTB respond to the presence of carbondioxide by changing color.

Step-by-step explanation:

Bromthymol blue is a chemical indicator dye that changes it color to yellow in the presence of an acid. It respond in the presence of carbondioxide and form carbonic acid, therefore lowering the pH. It becomes blue if the pH is greater than 7.6, it is green if the pH is between 6-7.6 and yellow if the pH is less than 6.