Question

If a solution is undergoing a reaction where CO2 is being created a product, what color is the phenol red-containing solution shifting toward?

Answer 1

Answer:

YELLOW

Explanation:

Phenol red is a biological indicator used to monitor changes in pH. The phenol red indicator changes color ranging from yellow to pink with respect to changes in pH. In an acidic pH i.e. <7, the phenol red changes to a YELLOW color while in an alkaline pH i.e. >7, the phenol red changes to a PINK pH.

The presence of carbon dioxide (CO2) increases the hydrogen ion concentration (H+) of a solution (lowering its pH or making it acidic).

Therefore, in a reaction where CO2 is created as a product, it means the CO2 content of that solution increases. Hence, the phenol red solution will be shifting towards the YELLOW color in response to a decreasee in pH (acidic).