Question

Question
How does the bromothymol solution change color when CO2 is added?
Responses

It turns from blue to yellow
It turns from blue to yellow

It becomes colorless
It becomes colorless

It turns from green to dark blue
It turns from green to dark blue

It turns from yellow to blue
It turns from yellow to blue

Answer 1

It turns from blue to yellow.
CO2 dissolves to form carbonic acid (H2CO3), lowering the pH; bromothymol blue shifts from blue (alkaline) through green (neutral) to yellow (acidic).