Question

Mark measures the volume of water in a beaker marked in 50-ml intervals. He reports the volume is 43.927 ml. What is misleading about this value?

Answer 1

The scale to determine laboratory level any liquid is generally milliliter (mL). Now in a beaker which is marked in 50 mL intervals there reporting the volume 43.927 mL of a certain liquid from the beaker is not feasible. And if done there will be serious error. The value of the liquid volume can be measured from the beaker preciously must be in terms of 50 mL that is 50, 100, 150, 200 mL etc. Thus the misleading about the value are-

1. The value is measured by any experiment or calculation, because if its through experiment by 50 mL marked beaker it is not possible.

2. The volume is been measured by the same beaker or not.

3. The accuracy and precision of the result is questionable.

Answer 2

A beaker ordinarily is not a standard laboratory glassware used in measuring a liquid, what is rather used is a measuring cylinder (also called graduated cylinder).

For a measuring cylinder, the "calibration" (marked intervals) of the cylinder is usually close (on the body of the cylinder) and accurate depending on the volume to be measured and the corresponding choice of measuring cylinder to be used. For example, an accurate measurement of 10.3 ml, one should choose a measuring cylinder that is marked 0.1 ml intervals.

In the case of a beaker, assuming the marked values are accurate, the marked intervals are usually far apart on the body of the beaker and it cannot be used to determine volumes that do not fall (lower meniscus) exactly on the mark. This means that, if the highest marked position on a beaker is 250 ml and the beaker is marked in 50-ml intervals, one can only measure 50 ml, 100 ml, 150 ml, 200 ml and/or 250 ml accurately in this beaker.

Thus, one cannot measure just 1 ml below or above this marked volumes. Hence, Mark could not have possibly determined a volume of less than 50 or of 43 (and definitely not 43.927) using that beaker.

In conclusion, the value 43.927 ml is misleading because this value cannot be measured using a beaker marked in 50-ml intervals.