What Effect Does Carbon Dioxide Have On the pH Indicator BTB?

Bromothymol blue (BTB) is a pH indicator that changes color depending on the pH of the solution it’s added to. A fun and simple way to observe this phenomenon is by blowing through a straw into a glass of water containing a few drops of BTB. The carbon dioxide in your breath changes the pH of the solution, which can be qualitatively measured by the color change of the BTB.

Topics

• pH
• proton concentration
• solution
• acid
• acidity
• pH scale
• interactive
• measuring
• proton
• pH value
• indicator
• pH indicator BTB
• Bromothymol blue
• photosynthesis
• carbon dioxide
• BTB