A Look at Density and How to Calculate It. Diggin’ That Density A Look at Density and How to Calculate It.

Remember Back Mass- Amount of matter something is made of. Volume – Amount of Space something takes up. It is 3-Dimensional

Remember Back Mass- Measured in grams (g). Volume – Measured in milliliters (mL) or in cubic centimeters (cm³)

Remember Back Mass is how much of something you have. So volume is the amount of space you have and….

Bring it Together Density is a combination of volume and mass. Density is the amount of matter in a given volume. The amount of “stuff” in a certain “space”

Figuring it Out There is a mathematical formula for calculating density. Density = Mass  Volume D = M  V

Units for Density Just like length, volume and mass density has to be labeled with the correct unit. g/cm³ or g/mL is the standard unit for density. Remember that a cm³ is basically the same as a mL.

D. Density V = 825 cm3 M = DV D = 13.6 g/cm3 M = (13.6 g/cm3)(825cm3) An object has a volume of 825 cm3 and a density of 13.6 g/cm3. Find its mass. GIVEN: V = 825 cm3 D = 13.6 g/cm3 M = ? WORK: M = DV M = (13.6 g/cm3)(825cm3) M = 11,220 g

D. Density D = 0.87 g/mL V = M V = ? M = 25 g V = 25 g 0.87 g/mL 1) A liquid has a density of 0.87 g/mL. What volume is occupied by 25 g of the liquid? GIVEN: D = 0.87 g/mL V = ? M = 25 g WORK: V = M D V = 25 g 0.87 g/mL V = 28.7 mL

D. Density M = 620 g D = M V = 753 cm3 D = ? D = 620 g 753 cm3 2) You have a sample with a mass of 620 g & a volume of 753 cm3. Find density. GIVEN: M = 620 g V = 753 cm3 D = ? WORK: D = M V D = 620 g 753 cm3 D = 0.82 g/cm3

Let’s Practice Liquid E had a mass of 82.61g. You massed 100mL of this liquid. Plug it into the formula.

Let’s Practice D = 82.61g  100mL D = .8261g/mL

Will it Float? Density can predict if something will float. How?

Will it Float? The object with a higher density than water sinks. If it has lower density it floats.

Density of Water Using our results from yesterday, what is the density of sea water? 100.84 g  100 mL = 1.0084 g/mL.

Measuring water If you wanted to measure 25ml of water, what instrument would you use?

Density of Water Calculate the density of water One milliliter of water Has a mass of 1 gram Density = Mass ÷ Volume Calculate the density of water 1g ÷ 1ml = 1g/ml

Measuring water If you wanted to measure 25ml of water, what instrument would you use?

Measuring water 2 If you wanted to measure 25 grams of water, what 2 instruments could you use?

Measuring volume of a solid by water displacement

One cubic centimeter = one milliliter Using water displacement, how many milliliters do you expect the water to raise when the cube is lowered? This cube’s sides are each 3 cm. What is the volume of the cube? 27 cubic cm 27 ml

Graduated cylinder measurement Volume is measured using a graduated cylinder. When reading a graduated cylinder, read the bottom of the meniscus.