what color does bromothymol blue turn in acidic conditions
Bromothymol blue (also known as bromothymol sulfone phthalein and BTB) is a pH indicator. It is mostly used in applications that require measuring substances that would have a relatively neutral pH (near 7). A common use is for measuring the presence of carbonic acid in a liquid.
Using teacher directed instruction and class discussion, ensure that the students understand the following points: BTB is blue in a neutral solution and yellow in a weak acid. When carbon dioxide from the lungs is exhaled into the BTB, it reacts with water to form carbonic acid: