In an experiment, acid was added to two solutions:

Solution 1: distilled water only

Solution 2: distilled water containing sodium bicarbonate

Then, the pH of each solution was taken.

Solution 1 had a final pH of 4.5, while Solution 2 had a final pH of 6.8.

Which of the following statements explains the difference between the two solutions?

Choose 1

(Choice A)

Sodium bicarbonate acted as a pH buffer in Solution 2.

(Choice B)

Hormones released in Solution 2 allowed it to maintain a higher pH.

(Choice C)

The water in Solution 1 had a lower starting pH than the water in Solution 2.

(Choice D)

Sodium bicarbonate increases the temperature of a solution, which helped raise the pH of Solution 2.

Sodium bicarbonate acted as a pH buffer in Solution 2.

Explanation:

One the other hand, sodium bicarbonate is alkaline in nature and has pH of 8.4. When an acid is added to a solution containing sodium bicarbonate, it will act as a pH buffer for acid and neutralize the acidic effect.

Other options are incorrect because there are no hormones added neither they will be produced or released during the reaction.

Also, lower initial pH of the solution 1 will not help to increase the pH after addition of acid.

Neither change in temeprature can change the pH.

both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.