oneCS-6B

Objective: To determine if substances will sink or float in order to conclude about their relative densities.CSI Note: Why do substances sink or float?

HAVE YOU FOLLOWED THE STEPS FOR STARTING CLASS??

Drill: 1. Get a Lesson Sheet from the

SET.2. Complete the Drill portion

only.

Density of Liquids

oneCS-6B

Let’s Review 

Density of Liquids

oneCS-6B

To find the density:

Divide the mass by the volume.

Density = Mass ÷ Volume

Density of Liquids

oneCS-6B

Units for Density: g/mL or g/cm3

 

Density of Liquids

oneCS-6B

**The density of a substance at a given

temperature is the same for all samples of that

substance, thus making density a characteristic

property.

Density of Liquids

oneCS-6B

HOMEWORK CHECK 

Density of Liquids

oneCS-6B

Calculate the density: Show 3 lines of work. (2 decimal places)

Substance 1: Mass = 85 g Volume = 10 cm3

 Density = Mass ÷ Volume

 

Density = 85 g ÷ 10 cm3

 

Density = 8.5 g/cm3

Density Of Liquids

oneCS-6B

Calculate the density: Show 3 lines of work. (2 decimal places)

Substance 2: Mass = 150 g Volume = 2.5 cm3

 Density = Mass ÷ Volume

 

Density = 150 g ÷ 2.5 cm3

 

Density = 60 g/cm3

Density Of Liquids

oneCS-6B

Calculate the density: Show 3 lines of work. (2 decimal places)

Substance 3: Mass = 33.92 g Volume = 3.2 cm3

 Density = Mass ÷ Volume

 

Density = 33.92 g ÷ 3.2 cm3

 

Density = 10.6 g/cm3

Density Of Liquids

oneCS-6B

If you had 200g of Substance 1, what would the density of

the substance be?

8.5 g/cm3

Density Of Liquids

oneCS-6A

If you had 5.0 cm3 of Substance 2, what would the density of the substance be?

60 g/cm3

Density Of Liquids

oneCS-6B

If you had any amount of Substance 1, what would the density of the substance be?

8.5 g/cm3

Density Of Liquids

oneCS-6B

WHY????

Density is a characteristic property!!! It does not

change for a given substance!!!

Density Of Liquids

oneCS-6B

Review Activity 

a. Look at your tag.b. Compute the density of

your substance.c. Based on the density,

locate all of the students that could possibly have the same substance.

Density Of Liquids

oneCS-6B

Think about these questions.

What will grains of sand do when dropped in water?

How much might a cruise ship weigh?

Do you need to make any corrections to your drill answer?

Density Of Liquids

oneCS-6B

Why do substances sink or float?

It’s not based on the weight.

It’s based on the density.

Density Of Liquids

oneCS-6B

Substances that are more dense than the substance they

are in tend to sink. Substances that are less

dense than the substance they are in tend to float.

Density Of Liquids

oneCS-6B

THE DENSITY OF WATER IS 1 g/cm3.

 What does this mean?

Density Of Liquids

oneCS-6B

Use your knowledge of sinking and floating and the density of

water to complete the chart in your lab.

Density Of Liquids

oneCS-6B

You may not always know the exact densities of substances, but you can tell the relative densities of substances (whether one substance is more or less dense than another) based on sinking and floating. This concept is used when creating a density tube.

Density Of Liquids

oneCS-6B

1. Look at the information below. 

Substance 1 Density = 7.03 g/cm3

Substance 2 Density = 7.2 g/cm3

Substance 3 Density = 7.15 g/cm3

Substance 4 Density = 0.75 g/cm3

2. Order the substances by their

densities from least to greatest.3. Diagram how the substances will layer.

Density Of Liquids

oneCS-6B

Density Tube

http://www.youtube.com/watch?v=-CDkJuo_LYs

Extra Credit

 

Density Of Liquids

oneCS-6B

Homework: In you Log Book, write

about 3 things you learned today.

Density Of Liquids