This experiment explored just how aerobic respiration from exercise affects a straightforward solution and also its transition to one acid. An ext energy is used during exercise, much more oxygen is forced in the human being body to fuel to move respiration. To move respiration produces energy in the kind of ATP and releases CO2 as a byproduct. It’s equation is glucose + oxygen → carbon dioxide + water; C6H12O6 + 6O2→ 6CO2 + 6H2O. (Dimand et al, 2002). This supports the prediction that longer durations of exercise will result in higher rates that carbon dioxide produced.

You are watching: Bromothymol blue experiment



To inspection the effects of aerobic respiration, four Erlenmeyer flasks were filled through distilled water to have a starting point v a neutral pH level. Fifty percent a pipette the Bromothymol Blue was included to the water together an mountain indicator v colors that ranged from acidic yellow to neutral green, then basic blue.

Three world performed the practice of running stairs for increments that one two and three minutes, for this reason respiration can be reached. Each human being blew with a straw right into the solution and also measured the quantity of time it took to change the neutral environment-friendly water come acidic yellow with the enhancement of carbon dioxide.

Sodium Hydroxide (NaOH) is a base the was used to go back to the neutral state that was measured against the control flask of environment-friendly distilled water for this reason we can ensure consistency. The times because that each increment to be recorded, averaged, and also graphed ~ above a scatter plot come depict the trend.


This data concludes that together the term of exercise increased, the moment it took to change the flask from a neutral come an acid both increased and also decreased. The guess outcome was that the moment to revolve to acid would decrease as exercise duration went up, This is sustained by the reality that greater exercise rates mean increased respiration i m sorry produces more CO2 that alters a basic to an acid.

The exhalation that carbon dioxide right into the substance produced a carbonic acid, which led to a change in the pH level. This adjust was suggested by bromothymol blue, seeing that the substance went back from a green shade to that yellow acidic state. As watched in Graph 1 over there is not lot data since the averages of all of the trials were taken which was only four points and they had actually a weak correlation, so a trend cannot really be produced.

The experiment was regulated by equivalent the neutral beginning point come a control flask that was a set green color. This in addition to the reality that resting heart rate was reached before each trial ensured that whatever started at the same point.

Some errors might be found in the fact that there was soap residue in some of the flasks that led to the mixture come foam up and also prohibited the from transforming all the means to an acid since soap is basic. This can be fixed by rinsing the flasks well v water before use. This would avoid inaccuracies while it take away to change to acidic.

See more: Kingdom Death Forge God - I Painted For A Commission

The much faster the price of respiration, the greater the price of oxygen use and the better the rate of carbon dioxide relax (BBC, 2014). With knowing this, one can predict that if someone to be to exercise an extremely rapidly, much more and more and much more carbon dioxide would certainly be expelled. Another question that can be researched is whether different species of practice cause more respiration contrasted to others through variables of task and time the takes a basic solution to come to be acidic.

Works Cited:

BBC. (2014). Respiration. Retrieved November 21, 2017, indigenous

Dimand, J., & B. B. (2002). Respiration Rates amongst exercising and also resting crickets. Recall November 20, 2017, from