Characteristic Physical Properties

Some examples of quantitative physical properties include:

• Density • Freezing point• Melting point• Boiling point

These properties can be used to identify a pure substance.

DENSITY• density is the amount of matter per unit

volume of that matter

DENSITY

To calculate the density of a substance, we need two pieces of information;1. mass

• measured in mg, g, kg using a scale or balance

2. volume • measured in mL, L using a graduated cylinder

or cm3, m3 using a ruler

DENSITY

To calculate the density of a substance, use the following equation:

mD V

Determining Mass

Triple Beam Balance

Reading a Triple Beam Balance

Reading a Triple Beam Balance

Reading a Triple Beam Balance

Measuring the Volume of a Rectangular Solid

Volume = length x width x height

V = l w h

Measuring the Volume of a Spherical Solid

= 3.14

Measuring the Volume of a Cylinder

= 3.14

V = r2 h

Measuring the Volume of a Liquid

Graduated Cylinder

Reading a Graduated Cylinder

Reading a Graduated Cylinder

Reading a Graduated Cylinder

Reading a Graduated Cylinder

Bottom of meniscus6.6 mL

Example #1

Reading a Graduated Cylinder

Bottom of meniscus

Example #2

53 mL

Measuring Volume of a Small Irregular Object

Displacement Method

• Fill graduated cylinder partially with water

• Read initial volume• Place in solid• Read final volume

Volume solid = Volume final – Volume initial

Measuring Volume of a Small Irregular Object by Displacement of Water in a Graduated Cylinder

Measuring Volume of a Large Irregular Object

Overflow Method

• Fill overflow can until water starts to pour out• Place in solid• Collect the overflow water in a graduated cylinder

Volume solid = Volume overflow

Measuring Volume of a Large Irregular Object by Displacement of Water in an Overflow Cup

GivenState what the question is giving you.(Don’t forget the symbols and units)

m = 12 gV = 15 mL

RequiredWhat does the question ask you to find?Use appropriate symbols.

D = ?

AnalysisRearranged equation that you will use to answer the question.

D = m / V

SolveSolve the problem. Make sure to include the units.

StatementMake a statement with the answer and units.

the density of the liquid is 0.80 g/mL.

The GRASS Method for Problem Solving

Example 1:A softball has a mass of 360 g and a volume of 270 cm3. Find its density.

Given: Required:

Analysis: Solution:

Statement:

Mass, m = 360 gVolume, V = 270 cm3

Density, D in g/cm3

D = 360 g 270 cm3

D = 1.33 g/cm3

the density of the softball is 1.33 g/ cm3

𝐷=𝑚𝑉

𝐷=𝑚𝑉

Example 2:Calculate the density of a metal sample that is 18.00 cm long, 9.21 cm wide, and 4.45 cm high and that has a mass of 14.25 kg. What is the identity of the metal?

Given:

Required:

Analysis:

l = 18.00 cm m = 14.25 kg w = 9.21 cmh = 4.45 cmV (cm3)D (g/cm3)

V = lwh 𝐷=𝑚𝑉

Solution:

Statement:

D = 14.25 kg 738 cm3

D = 0.0193 kg/cm3

the density of the metal is 19.3 g/cm3

The metal is gold.

Example 2:Calculate the density of a metal sample that is 18.00 cm long, 9.21 cm wide, and 4.45 cm high and that has a mass of 14.25 kg. What is the identity of the metal?

V = l w hV = (18.00 cm)(9.21 cm)(4.45 cm) V = 738 cm3

D = 19.3 g/cm3

𝐷=𝑚𝑉

• Density Problems Worksheet• pg. 198 #1, 3-10

Test (Chapter 5) – Thursday Sept 18

Homework: