Question

question



A student poured a solution of bromothymol blue indicator into three test tubes. Then he placed an aquatic plant in two of the test tubes, as shown below. He placed a stopper on each test tube and placed them all in the dark for 24 hours. Bromothymol blue turns from blue to yellow in the presence of CO2


Predict what will happen to the test tubes in Figure 9–9 after 24 hours in the dark.

Answer 1

In the dark the aquatic plant won't do photosynthesis. Instead it will do cellular respiration in which it will produce CO2. Therefore after 24 hours of letting the plant in the dark introducing Bromothymol in the solution will cause it to turn yellow.