To find the volume of a liquid in a graduated cylinder, read the measurement at the bottom of the meniscus (the curved surface of the liquid).
Here's a more detailed breakdown:
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Place the Cylinder on a Flat Surface: Ensure the graduated cylinder is sitting on a level surface to avoid parallax errors.
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Get Eye-Level with the Meniscus: Position yourself so that your eye is at the same height as the top of the liquid in the cylinder. This is crucial for an accurate reading.
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Identify the Meniscus: The surface of the liquid will curve. This curve is called the meniscus. For most liquids (like water), the meniscus is concave (curves downward). For some liquids (like mercury), it's convex (curves upward).
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Read the Bottom of the Meniscus (for Concave Meniscus): For liquids with a concave meniscus, read the volume at the bottom of the curve. This is the most accurate measurement.
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Estimate Between Graduations: The liquid level might fall between two markings. Estimate the value to the nearest tenth of a milliliter (or whatever the smallest graduation is). For example, if the meniscus is slightly above the 23 mL mark, you might estimate the volume as 23.2 mL.
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Account for Cylinder Calibration: Note the units on the graduated cylinder. Most often, volume is measured in milliliters (mL).
Example:
Let's say you have a graduated cylinder with markings every 1 mL, and smaller markings subdividing each mL into tenths (0.1 mL). If the bottom of the meniscus is between 25 mL and 26 mL, and it looks to be two small markings past the 25 mL mark, then your estimated volume is 25.2 mL. The video reference points out that if a large graduation (say, 5mL) is divided into 10 subgraduates, each subgraduate represents 0.5 mL.
