Question

Select Show oxygen and CO2 values. Place the O2/CO2 probe in each tube. The probe shows the levels of two gases, oxygen (O2) and carbon dioxide (CO2), in the tubes. We call these amounts the gas levels.

A. When the water turns blue, which gas is most common? ___Oxygen___________________
B. When the water turns yellow, which gas is most common? ___Carbon Dioxide__________________
C. What does it tell you when the water is green? ___The gas levels are both 6.0 and even. ________________

Answer 1

When the water turns yellow, it signifies higher carbon dioxide levels. Green water indicates even levels of oxygen and carbon dioxide at 6.0. For accurate oxygen consumption measurements, a CO2-absorbing substance must be added to the setup.

Step-by-step explanation:

The question relates to the measurement of oxygen (O2) consumption and carbon dioxide (CO2) production in an experimental setup involving animals. The use of an O2/CO2 probe allows the monitoring of gas levels within the test tubes. One of the constraints of assessing oxygen consumption is accounting for the production of CO2, which could alter the volume of gas in the tube.

When the water turns yellow, it indicates a higher level of carbon dioxide in the tube. If the water turns green, this suggests balanced gas levels, with both oxygen and carbon dioxide being at 6.0, indicating a neutral state. To ensure accurate measurements of oxygen consumption, one would need to add a substance that could absorb or react with the carbon dioxide produced, such as sodium hydroxide (NaOH), leaving only the changes in oxygen levels to be measured.