Dimensional analysis and Units of Measurements - PowerPoint Presentation

Slide1

Dimensional analysisand Units of MeasurementsSlide2

Dimensional analysis

Dimensional analysis

uses conversion factors to convert from one unit to another.

Also called Factor Label (and railroad tracks)

You do this in your head all the time

How many quarters are in 4 dollars? Slide3

Dimensional analysis practice

3 Big Mac = 7 salads

9 salads = 2 slices of pepperoni pizza

22 slices of pepperoni pizza = 27 Sonic cokes

Ex. 1) What number of Big Macs equal 365.4 salads?

Ex. 2) How many sonic cokes do you have to drink to equal 11 salads?Slide4

Units of Measurement

Meter m

Liter L

Celsius CSlide5

Mass is the amount of matter,

weight

is a measure of the gravitational pull on matterSlide6

SI Units

Prefix

Symbol

Scientific notation

Factor

Example

Mega

M

1 x 10

6

1,000,000

megagram (Mg)

Kilo

k

1 x 10

3

1,000

kilometer (km)

Hecto

h

1 x 10

2

100

hectoliter (hL)

Deka

da or (D)

1 x 10

1

10

dekagram (Dg)

BASE UNIT

1 x 10

0

1

meter

Deci

d

1 x 10

-1

.1

deciliter (dL)

Centi

c

1 x 10

-2

.01

centimeter (cm)

Milli

m

1 x 10

-3

.001

milligram (mg)

Micro

u

1 x 10

-6

.000001

microgram (ug)

Nano

n

1 x 10

-9

.000000001

nanometer (nm)

Pico

p

1 x 10

-12

.000000000001

picogram

(pg)Slide7

PracticeIn each pair below, circle the larger

Millimeter

Centimeter

picometer

Micrometer

kilogram

Hectogram

deciliter

millileterSlide8

PracticeIn each pair below, circle the larger

Millimeter

Centimeter

picometer

Micrometer

kilogram

Hectogram

deciliter

millileterSlide9

PracticeIn each pair below, circle the larger

Millimeter

Centimeter

picometer

Micrometer

kilogram

Hectogram

deciliter

millileterSlide10

PracticeIn each pair below, circle the larger

Millimeter

Centimeter

picometer

Micrometer

kilogram

Hectogram

deciliter

millileterSlide11

PracticeIn each pair below, circle the larger

Millimeter

Centimeter

picometer

Micrometer

kilogram

Hectogram

deciliter

millileterSlide12

Basic SI Units

Quantity

Base unit

Length

meter (m)

Mass

gram (g)

Time

second (s)

Volume

Liter (L)

Temperature

Kelvin (K) or Celsius (C)

Amount of substance

mole (mol)

Heat & Energy

joule (J)Slide13

Metric Conversions Practice

Ex. 3) 2

.

435

g __________________cg

Ex. 4) 23

.

8 mL = ________________kL

 Ex. 5) 23

.

5

cs

= ________________nsSlide14

Some Useful Conversions

Length:

1 in = 2.54 cm

1 mi = 5280 ft

Volume:

1 cm

3

= 1

mL

1 L = 1.06 qt

Weight:

1 kg = 2.2 lb

16 oz

= 1 lb

1

ton = 2000 lbSlide15
Slide16

Temperature

20°C =

K

Use both the Kelvin and Celsius scale,

to convert

Celsius + 273 = Kelvin

Kelvin -273 = CelsiusSlide17

Temperature

20°C =

293

K

Use both the Kelvin and Celsius scale,

to convert

Celsius + 273 = Kelvin

Kelvin -273 = CelsiusSlide18

Temperature

20°C =

293

K

373 K =

°C

Use both the Kelvin and Celsius scale,

to convert

Celsius + 273 = Kelvin

Kelvin -273 = CelsiusSlide19

Temperature

20°C =

293

K

373 K =

100

°C

Use both the Kelvin and Celsius scale,

to convert

Celsius + 273 = Kelvin

Kelvin -273 = CelsiusSlide20

Volume: measured in cubic centimeters (cm3

) or liters

1 liter (L) = 1 cubic decimeter (dm

3

) = 1000

millileters

(

mL

)1

mL= 1 cm3Slide21

Volume can be measure by

Length x

x

or the

Water Displacement method Slide22

Volume can be measure by

Length x

width

x

or

the

Water Displacement method Slide23

Volume can be measure by

Length x

width

x

height

or

the

Water Displacement method Slide24

Volume can be measure by Length x

width

x

height

or

the

Water Displacement method

Know the relationship between the following volume units

… L =

mL =

cm

3

(or cc in medical lingo)

Slide25

Volume can be measure by Length x

width

x

height

or

the

Water Displacement method

Know the relationship between the following volume units

… 1 L =

mL =

cm

3

(or cc in medical lingo)

Slide26

Volume can be measure by Length x

width

x

height

or

the

Water Displacement method

Know the relationship between the following volume units

… 1 L =

1000 mL =

cm

3

(or cc in medical lingo)

Slide27

Volume can be measure by Length x

width

x

height

or

the

Water Displacement method

Know the relationship between the following volume units

… 1 L =

1000 mL = 1000

cm

3

(or cc in medical lingo)

Slide28

Density

Is the ratio of mass per unit of volume. How much matter is packed into a given amount of space

Density = mass/volume

D= m/vSlide29

The Density of a substance stays

regardless of the size of the sample. For example: if you cut a block of copper in half, you have decreased

both

the mass and volume, the ratio of the 2 stays the same. This is called an

Intensive

Physical Property.Slide30

The Density of a substance stays constant

regardless of the size of the sample. For example: if you cut a block of copper in half, you have decreased

both

the mass and volume, the ratio of the 2 stays the same. This is called an

Intensive

Physical Property.Slide31

The appropriate units of density are:

for solids

for liquidsSlide32

The appropriate units of density are: g/cm

3

for solids

for liquidsSlide33

The appropriate units of density are: g/cm

3

for solids

g/

mL

for liquidsSlide34

Example problems:

A sample of aluminum metal has a mass of 8.4g. The volume of the sample is 3.1 cm

3

. Calculate the Density of aluminum. Slide35

Example problems:

A sample of aluminum metal has a mass of 8.4g. The volume of the sample is 3.1 cm

3

. Calculate the Density of aluminum.

8.4 g/3.1 cm

3

=Slide36

Example problems:

A sample of aluminum metal has a mass of 8.4 g. The volume of the sample is 3.1 cm

3

. Calculate the Density of aluminum.

8.4 g/3.1 cm

3

= 2.7 g/cm

3Slide37

Example problems:

Diamond has a density of 3.26 g/cm

3

. What is the mass of a diamond that has a volume of 0.350 cm

3

?Slide38

Example problems:

Diamond has a density of 3.26 g/cm

3

. What is the mass of a diamond that has a volume of 0.350 cm

3

?

3.26 g/cm

3

x 0.350 cm3 = Slide39

Example problems:

Diamond has a density of 3.26 g/cm

3

. What is the mass of a diamond that has a volume of 0.350 cm

3

?

3.26 g/cm

3

x 0.350 cm3 = 1.14 gSlide40

Example problems:

What is the volume of a sample of liquid mercury that has a mass of 76.2 g, given that the density of mercury is 13.6 g/

mL

?Slide41

Example problems:

What is the volume of a sample of liquid mercury that has a mass of 76.2 g, given that the density of mercury is 13.6 g/

mL

?

76.2 g =

13.6 g/

mL

Slide42

Example problems:

What is the volume of a sample of liquid mercury that has a mass of 76.2 g, given that the density of mercury is 13.6 g/

mL

?

76.2 g = 5.60

mL

13.6 g/

mL

Slide43

Reliable Measurements

refers to the closeness of the measure value is to the

, or real, value.

refers to how

a series of measurements are to one another.Slide44

Reliable Measurements

Accuracy

refers to the closeness of the measure value is to the

, or real, value.

refers to how

a series of measurements are to one another.Slide45

Reliable Measurements

Accuracy

refers to the closeness of the measure value is to the

accepted

, or real, value.

refers to how

a series of measurements are to one another.Slide46

Reliable Measurements

Accuracy

refers to the closeness of the measure value is to the

accepted

, or real, value.

Precision

refers to how

a series of measurements are to one another.Slide47

Reliable Measurements

Accuracy

refers to the closeness of the measure value is to the

accepted

, or real, value.

Precision

refers to how

close

a series of measurements are to one another.Slide48
Slide49

is calculated by

subtracting

the

value from the

value.Slide50

Error is calculated by subtracting

the

experimental

value from the

accepted

value.Slide51

The

is the ratio of an error to an accepted value. Slide52

The

percent error

is the ratio of an error to an accepted value. Slide53

% error = error x 100 = accepted value – experimental value

x

100

accepted value accepted valueSlide54

Example

An experiment finds the density of lead to be 10.95 g/cm

3

. The literature value for the density of lead is 13.34 g/cm

3

.Slide55

The error: accepted value – experimental value=

13.34 – 10.95 =

An experiment finds the density of lead to be 10.95 g/cm

3

. The literature value for the density of lead is 13.34 g/cm

3

.Slide56

The error: accepted value – experimental value=

13.34 – 10.95 =

2.39

An experiment finds the density of lead to be 10.95 g/cm

3

. The literature value for the density of lead is 13.34 g/cm

3

.Slide57

The error: accepted value – experimental value=

13.34 – 10.95 =

2.39

The % error: error x 100 =

accepted value

2.39 x 100 =

13.34 Slide58

The error: accepted value – experimental value=

13.34 – 10.95 =

2.39

The % error: error x 100 =

accepted value

2.39 x 100 = 17.9%

13.34 Slide59

Practice

Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0?Slide60

Practice

Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0?

28.9 – 27.0 =Slide61

Practice

Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0?

28.9 – 27.0 = 1.90Slide62

Practice

Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0?

28.9 – 27.0 = 1.90

1.90/27.0 x 100% =Slide63

Practice

Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0?

28.9 – 27.0 = 1.90

1.90/27.0 x 100% = 7.04%Slide64

Practice

What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C?Slide65

Practice

What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C?

60.8 °C – 40.6 °C = Slide66

Practice

What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C?

60.8 °C – 40.6 °C = 20.2 °CSlide67

Practice

What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C?

60.8 °C – 40.6 °C = 20.2 °C

20.2 °C / 60.8 °C x 100% = Slide68

Practice

What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C?

60.8 °C – 40.6 °C = 20.2 °C

20.2 °C / 60.8 °C x 100% = 33.2%