Volume of an Object Is a Measure of the Space Occupied by the Object

Name: Date: Period:

Measuring Volume

Volume of an object is a measure of the space occupied by the object

Volume is commonly measured in the following Metric units

Liter (L), milliliter (mL), cubic centimeter (cm3)

What are we measuring when we measure volume?

Amount of a liquid, space a solid occupies, displacement of a solid in a liquid, volume of a box (L x W x H), etc.

Tools and Instruments we use:

Graduated cylinders, beakers, Erlenmeyer flasks, pipettes, eye droppers, rulers, measuring tape

When scientists talk about how big something is, they are really talking about its volume, or the amount of space it occupies or it takes up.

Measuring the volume of liquids we commonly use graduated cylinders, beakers, pipettes, and eye droppers in the lab. Graduated cylinders are precise tools for measuring volume. Most graduated cylinders are marked in milliliters (remember there are 1,000 milliliters in 1 liter).

Measuring volume of a solid we commonly use rulers, measuring tapes, or process of displacement. The volumes of regular solids, such as spheres (balls) and rectangular prisms (blocks), can be determined by measuring their dimensions. The volume of a solid is usually expressed in cubic centimeters (cm3). One cubic centimeter (cm3) is exactly the same volume as 1 milliliter (mL).

Have you ever climbed into a tub and seen the water rise? The amount the water rises is related to your size—the bigger you are, the more the water will rise. This method, called water displacement, can be used to measure volume of an irregular solid.

Irregularly shaped solids

Water displacement is used to measure the volume of oddly shaped solids. Start by using a graduated cylinder to fit the object being measured. Fill the cylinder with enough water to submerge the object. When the object is placed in the water, the water level will move. The volume of the object is equal to the difference between the starting and ending water levels.

When measuring the volume of the marble, why is it better to use the 25-mL graduated cylinder than the 100-mL graduated cylinder?

A solid with a regular shape can be measured with a METRIC RULER by finding its length, width, and height. The volume is calculated by multiplying these measurements together. If the length, width, and height are measured in centimeters, then the unit will be cubic centimeters (cm3).

Example:

20 cm x 6 cm x 25 cm = 3000 cm3

Liquids

The volume of a liquid is measured in a GRADUATED CYLINDER. These tools come in a variety of sizes to measure various amounts of liquids. To read a graduated cylinder, the person reading the instrument must move their eyes even with the liquid in the cylinder. Because of the properties of liquids, a small curve is created inside of the cylinder. This is called a meniscus. The number of millimeters is measured at the bottom of the meniscus.

Example:

The bottom of the meniscus is at 56 mL.