IMAGE. 100-mL graduated cylinder.
Step 1: Determine the scale increment:
To find the scale increment, subtract the values of any two
adjacent labeled graduations and divide by the number of intervals
What is the scale increment for the 100-mL graduated cylinder? Answer
In the 100-mL graduated cylinder shown, the labeled graduations are 60 and 50 mL. So, subtract 60 mL - 50 mL = 10 mL. Next, count that there are ten intervals between the labeled graduations. Therefore, the scale increment is 10
mL/10 graduations = 1 mL/graduation.
Step 2: Use the graduations to find all certain digits:
Use the labeled graduations and the scale increment to find
the certain digits in the measurement.
What are all of the certain digits for solution in the 100-mL graduated cylinder shown? Answer
The volume is greater than 50 mL, since the last labeled graduation below the meniscus is 50. Next, use the scale increment. There are two graduation marks below the meniscus, and each graduation represents 1 mL, so the certain digits of the reading are 52 mL.
Step 3: Estimate the uncertain digit and obtain a reading:
Estimate the distance that the meniscus lies between the two graduations as a decimal fraction and multiply by the scale increment.
What is the volume you should record for the solution in the image above?
The meniscus is about nine tenths of the way to the next graduation, so the final digit in the reading is (0.9 increment) * (1 mL/increment) = 0.9 mL. The uncertain reading is added to the certain digits, so the volume measurement is 52.9 mL.