What is the precision of a 25 mL volumetric pipette?

0.03 mL
volume 25 mL, accuracy: 0.03 mL.

What is the tolerance of a pipette?

ASTM standard E969 defines the standard tolerance for volumetric transfer pipettes. The tolerance depends on the size: a 0.5-mL pipette has a tolerance of ±0.006 mL, while a 50-mL pipette has a tolerance of ±0.05 mL.

What is the uncertainty of a 25 mL graduated cylinder?

Making a measurement A 100-ml graduated cylinder with 1-ml graduation will have an uncertainty of +0.1mL. For a 25-ml graduated cylinder with graduation of 0.2 ml, the uncertainty is +. 02-ml (10% of 0.2 = . 02).

What is glassware tolerance?

Tolerance is the permissible deviation from a specified value. All volumetric glassware has some tolerance for accuracy – that is, all glassware contains or delivers volumes that can be slightly different from the stated volume that is printed on the glassware. Class A glassware is more accurate that Class B.

What is the uncertainty of a 25 mL pipette?

How do you calculate a pipette error?

Then measure the relative standard deviation in the dispensed masses by calculating the standard deviation and expressing it as a percentage of the average. This is your pipetting error.

How many decimal places do you read a 25 mL graduated cylinder?

25 mL graduated cylinders let you measure volumes up to 25.0 mL to the nearest 0.05 or 0.02 mL, depending on your exact cylinder. 50 mL graduated cylinders let you measure volumes up to 50.0 mL to the nearest 0.1 or 0.2 mL, depending on your exact cylinder.

Which glassware is the most precise?

Volumetric pipets, flasks and burets are the most accurate; the glassware makers calibrate these to a high level of accuracy. The accuracy is usually measured in terms of the tolerance, which is the uncertainty in a measurement made with the glassware.

What is tolerance of volumetric glassware?

Even Class A volumetric glassware is not absolute but rather has a tolerance from its stated nominal value. For example, a 25 mL Class A Transfer Volumetric Pipet has a capacity tolerance of ± 0.03 mL, and a 50 mL Class A Buret has a tolerance of ±0.05 mL at full capacity.

What is the uncertainty for mL?

In the graduated cylinder shown in Figure 1, the mL graduations are marked and can be read with certainty. All graduated glassware is read with one estimated digit, so this measurement is recorded correctly to the nearest 0.1 mL, with an understood uncertainty of ± 0.1 mL.

What is a good percentage uncertainty?

Explanation: In some cases, the measurement may be so difficult that a 10 % error or even higher may be acceptable. In other cases, a 1 % error may be too high. Most high school and introductory university instructors will accept a 5 % error.

What is the tolerance on a pipette at 20ºC?

The pipette may have the tolerance written on the side as: ± 0.26 ml @ 20ºC This means that when the pipette is used exactly as per the manufacturer’s instructions at 20ºC there is an in-built inaccuracy of between + 0.26 ml and – 0.26 ml.

Is there a limit to the size of a pipette?

Balancing this interplay of factors can make it a challenge to develop achievable tolerance limits for pipettes. This Lab Report reviews the key issues that should be considered when establishing tolerance limits for the working laboratory, and recommends a set of achievable tolerance limits for single and multi-channel pipettes of various sizes.

What are the volumes of a volumetric pipette?

Typical volumes are 1, 2, 5, 10, 20, 25, 50 and 100 mL. Volumetric pipettes are commonly used in analytical chemistry to make laboratory solutions from a base stock as well as to prepare solutions for titration. ASTM standard E969 defines the standard tolerance for volumetric transfer pipettes.

What are the relative errors of burette and pipette?

Maximum relative errors for A class volumetric glassware capacity mL pipette pipette burette burette 25 0.030 0.12 0.030 0.15 50 0.050 0.10 0.050 0.13 100 0.080 0.08 0.100 0.13 200 0.100 0.05