Why does phenol red turn yellow with your breath and carbonated water if it is an acid indicator?

Question

Why does phenol red turn yellow with your breath and carbonated water if it is an acid indicator?

Answer 1

At pH 7, phenol red is tomato color. It turns purplish red at alkali pH and yellow at acidic pH. When you breathe into water, CO2 dissolves in water and forms carbonic acid. That is why phenol red turns yellow.

Answer 2

Carbon dioxide  

Answer 3

Well, then what do you think about the expirated air and moreover about carbon dioxide? its acidic yaar......

Answer 4

Well you answered your question already. Phenol red indicates the presence of an acid within the solution when it turns yellow and it turns yellow if you breathe into it or put with carbonated water.

I'll give you another hint as to which acid, the water is carbonated with some gas thats awefully similar to a gas that we breathe out as per normal respiration requirements