Uploaded August 2025 | Updated September 2026, 2 weeks ago
How To Accurately Measure Liquid Volume
Dr. DeBacco
Measuring Volume… Beaker?
Be sure to use equipment intended for accurate volume readings.
Note: Beakers and Flasks are not intended for accurate readings.
*Select the correct size for the intended volume to be measured.
Reading the Meniscus
The meniscus is the curved upper surface of a liquid in a container, caused by surface tension and the relative attraction of the liquid to the container and to itself.
Always read from the apex of the curve.
For most liquids this will be the bottom of the meniscus.
Ex. Mercury will have an inverse or convex meniscus curve.
Concave Meniscus
Most liquids, like water in a glass, have a concave meniscus, where the liquid curves upward along the container walls.
This is because the adhesive forces between the liquid and the container are stronger than the cohesive forces within the liquid.
Convex Meniscus
In contrast, mercury and other liquids with strong cohesive forces have a convex meniscus, where the liquid curves downward away from the container walls.
This happens because the attraction between mercury atoms is stronger than their attraction to the glass.
Make sure Readings are taken Eye Level
Avoid Parallax errors by reading at eye level.
Common Equipment
Graduated Cylinders
Burette
Measuring and Sig Figs
Read the volume using all certain digits and one uncertain digit.
Certain Digits- Digits in a measurement that are known with complete confidence based on the measurement device's scale or calibration.
Uncertain Digits- The estimated digit in a measurement, representing the best guess between the smallest divisions of the measuring instrument.
Measuring Volume in Action
For a titration setup with a burette, the volume readings from the burette involve certain and uncertain digits.
If the burette is marked in 0.1 mL increments and you read 25.3 mL, the 25 and 3 are certain (directly read) digits, but if you estimate to 25.34 mL, the 4 is uncertain.
Step 1: Find All Certain Digits
There are two unlabeled graduations below the meniscus, and each graduation represents 1 mL, so the certain digits of the reading are…
52mL
Step 2: Estimate the Uncertain Digit
The meniscus is about eight tenths of the way to the next graduation, so the final digit in the reading is 0.8mL
Link to Lecture Slides: drive.google.com/file/d/1gnXA70NuEZ9EvcibmCUSvh9ScqsLmWve/view?usp=drive_link
*Due to the description character limit the full work cited for "How to Accurately Measure Liquid Volume" can be viewed at... docs.google.com/document/d/1f-_PV9lj4sPMkl6ov3f9TEA1XmBNeITI/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
How To Accurately Measure Liquid Volume
Dr. DeBacco
Measuring Volume… Beaker?
Be sure to use equipment intended for accurate volume readings.
Note: Beakers and Flasks are not intended for accurate readings.
*Select the correct size for the intended volume to be measured.
Reading the Meniscus
The meniscus is the curved upper surface of a liquid in a container, caused by surface tension and the relative attraction of the liquid to the container and to itself.
Always read from the apex of the curve.
For most liquids this will be the bottom of the meniscus.
Ex. Mercury will have an inverse or convex meniscus curve.
Concave Meniscus
Most liquids, like water in a glass, have a concave meniscus, where the liquid curves upward along the container walls.
This is because the adhesive forces between the liquid and the container are stronger than the cohesive forces within the liquid.
Convex Meniscus
In contrast, mercury and other liquids with strong cohesive forces have a convex meniscus, where the liquid curves downward away from the container walls.
This happens because the attraction between mercury atoms is stronger than their attraction to the glass.
Make sure Readings are taken Eye Level
Avoid Parallax errors by reading at eye level.
Common Equipment
Graduated Cylinders
Burette
Measuring and Sig Figs
Read the volume using all certain digits and one uncertain digit.
Certain Digits- Digits in a measurement that are known with complete confidence based on the measurement device's scale or calibration.
Uncertain Digits- The estimated digit in a measurement, representing the best guess between the smallest divisions of the measuring instrument.
Measuring Volume in Action
For a titration setup with a burette, the volume readings from the burette involve certain and uncertain digits.
If the burette is marked in 0.1 mL increments and you read 25.3 mL, the 25 and 3 are certain (directly read) digits, but if you estimate to 25.34 mL, the 4 is uncertain.
Step 1: Find All Certain Digits
There are two unlabeled graduations below the meniscus, and each graduation represents 1 mL, so the certain digits of the reading are…
52mL
Step 2: Estimate the Uncertain Digit
The meniscus is about eight tenths of the way to the next graduation, so the final digit in the reading is 0.8mL
Link to Lecture Slides: drive.google.com/file/d/1gnXA70NuEZ9EvcibmCUSvh9ScqsLmWve/view?usp=drive_link
*Due to the description character limit the full work cited for "How to Accurately Measure Liquid Volume" can be viewed at... docs.google.com/document/d/1f-_PV9lj4sPMkl6ov3f9TEA1XmBNeITI/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
