Question

different pieces of equipment allow for measurements with different levels of precision. for example, a graduated cylinder with 0.1 - ml divisions allows for more precise measurements than a graduated cylinder with 1 - ml divisions. when recording measurements, the smallest division on the equipment indicates how precise the data you record should be.
it is appropriate to estimate a value that is 1/10th the size of the smallest division on a measurement tool. if using equipment that clearly indicates the tenths place, you could record a value with an estimated digit in the hundredths place. for example, if a volume appeared to be between 36.2 and 36.3 ml, the volume could be recorded as 36.25 ml. the 5 in the hundredths place is the estimated digit.
figure 13: the smallest division shown on a piece of equipment indicates how precise data obtained with that equipment should be.
explain from left to right, the name and smallest division marked on each piece of equipment in figure 13 is: graduated cylinder (2 ml), erlenmeyer flask (25 ml), beaker (10 ml), and volumetric flask (100 ml).
which of these pieces of equipment would be the most appropriate for precisely measuring 29 ml of liquid? explain your reasoning, citing evidence related to the divisions on each tool and the concept of an estimated digit.
evidence notebook describe an example of a situation when very precise measurements would be important. then, describe an example of a situation where estimated values would be acceptable. why are these situations different?

Explanation:

The graduated cylinder with 2 - mL divisions is the most appropriate. The Erlenmeyer flask has 25 - mL divisions, which are too large (a 29 - mL measurement would be between 0 and 25 or 25 and 50, with a large error range). The volumetric flask is for a specific volume (100 mL here) and not for measuring 29 mL. For the graduated cylinder, since the smallest division is 2 mL, we can estimate to the tenths (1/10 of 2 mL = 0.2 mL). A measurement of 29 mL (could be estimated as 29.0 mL considering the 2 - mL divisions and the estimated digit concept). The beaker has 10 - mL divisions. A 29 - mL measurement in a beaker would be between 20 and 30 mL. The error range (± 5 mL for a 10 - mL division when estimating 1/10 of the division, so ± 1 mL) is larger than that of the graduated cylinder (error range ± 1 mL for 2 - mL division when estimating 1/10, so ± 0.2 mL).

Answer:

The graduated cylinder.