Question

check all the ways listed below that ensure accurate reading of volume from a graduated pipette.
tapping the base of the pipette on the table
using subtraction to determine the volume dispensed
making sure that you read the volume with the liquid inside the pipette at eye level
reading only the final volume of liquid after dispensing
ensuring that air bubbles are not in the column of liquid inside the pipette
done

Explanation:

• Tapping the base: Can remove air bubbles but not a primary way for accurate reading.
• Using subtraction: For pipettes that measure by difference (initial - final), this is correct.
• Eye - level reading: Essential to avoid parallax error for accurate volume reading.
• Reading only final: Incorrect, as some pipettes require initial - final subtraction.
• No air bubbles: Air bubbles displace liquid, so removing them ensures accurate volume.

Answer:

• using subtraction to determine the volume dispensed
• making sure that you read the volume with the liquid inside the pipette at eye level
• ensuring that air bubbles are not in the column of liquid inside the pipette