Question

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 answer:
Sodium bicarbonate increases the temperature of a solution, which helped raise the pH of Solution
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B
Sodium bicarbonate acted as a pH buffer in Solution 2.
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Hormones released in Solution 2 allowed it to maintain a higher pH
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The water in Solution 1 had a lower starting pH than the water in Solution 2.

Answer 1

Sodium bicarbonate acted as a pH buffer in Solution 2.

Step-by-step explanation:

The function of a pH buffer is to resist changes in pH in a solution by bonding hydrogen ions or dissociating into hydrogen ions to maintain pH.

In this case, sodium bicarbonate acted as a buffer by bonding the hydrogen atoms in the acid. Hence, the correct option is B.

A buffer usually consists of a weak acid and its conjugate base.