Assume that you are delivering a solution sample from a pipette. Figures (a) and (b) show the volume level before and after dispensing the sample, respectively. State the liquid level (in mL) before and after dispensing the sample, and calculate the volume of the sample. a.
b.

Verified step by step guidance

1. Observe the initial liquid level in figure (a). It is between 0.2 mL and 0.3 mL, closer to 0.3 mL.
2. Record the initial liquid level from figure (a) as 0.28 mL.
3. Observe the final liquid level in figure (b). It is between 0.2 mL and 0.3 mL, closer to 0.2 mL.
4. Record the final liquid level from figure (b) as 0.22 mL.
5. Calculate the volume of the sample dispensed by subtracting the final liquid level from the initial liquid level: 0.28 mL - 0.22 mL.

Key Concepts

Volume Measurement

Volume measurement is a fundamental concept in chemistry that refers to the amount of space occupied by a liquid. In this context, graduated cylinders are used to measure the liquid levels before and after dispensing a sample. Accurate reading of the meniscus, the curve formed by the liquid surface, is crucial for precise volume determination.

Pipetting Technique

Pipetting technique involves the proper use of a pipette to transfer liquids accurately. This includes understanding how to fill the pipette, dispense the liquid, and ensure that no residual liquid remains in the tip. Mastery of this technique is essential for obtaining reliable measurements in laboratory settings.

Calculating Volume Difference

Calculating the volume difference involves subtracting the final volume from the initial volume to determine the amount of liquid dispensed. This calculation is essential for quantifying the sample transferred and is a common practice in experimental procedures to ensure accuracy and reproducibility in results.