Question

Which of the following are serious sources of experimental error? Put a check mark in front of the choice.

a. The sodium hydroxide is not mixed completely in the flask.
b. The buret is not cleaned well before use.
c. The Acetic acid samples are dissolved in 10 mL or 20ml of distilled water before titration.
d. Two drops (not one drop) of phenolphthalein indicator is used.
e. Bubbles are not cleared from the tip of the buret.
f. The Erlenmeyer flasks are not dried before pipetting the vinegar samples.

Answer 1

The serious sources of experimental error are incomplete mixing of sodium hydroxide, insufficient cleaning of the buret, and inadequate drying of the Erlenmeyer flasks. The options (a), (b), and (f) are correct.

Step-by-step explanation:

The serious sources of experimental error are:

• a. The sodium hydroxide is not mixed completely in the flask.
• b. The buret is not cleaned well before use.
• f. The Erlenmeyer flasks are not dried before pipetting the vinegar samples.

These errors can affect the accuracy and precision of the experimental results. Incomplete mixing of sodium hydroxide can lead to inaccurate titration results, while insufficient cleaning of the buret and inadequate drying of the flasks can introduce impurities that affect the reaction. Therefore, options (a), (b), and (f) are correct.