Transcript Unit 3 - NordoniaHonorsChemistry

16 days
Day One
Syllabus HIGHLIGHTS!!!

Expectations
 Be Prepared
 NO FOOD OR DRINK IN THIS
CLASSROOM EVER!!!
How do I get a good grade?
 Hall Passes
 Absences

MISCELLANEOUS

BOOKS: Put name in front cover and
please cover the book!

Three ring binder

Calculator


Email
Lab Safety Contract
Lab Notebook

Labs
 Spiral bound notebook
 Lab procedure: found online and in the room
 Must be written in your lab notebook before you
begin lab as well as any data tables you may
need
 Completed with a partner but must be a
collaborative effort
 Each partner is responsible to have the data
before they leave the room
Lab Safety Video
Location of Safety Equipment






Goggles
Aprons
Sand
Eyewash station
Safety Shower
MSDS Sheets
Fire Blanket
 Fire extinguisher
 Emergency Stop
Button
 Fire Alarm
 Fume hood
 Broken Glass
Container
diagram
of the room

Assignment: Draw a
and
label the safety equipment listed above.
Explain what each of the above is used for and
when they are used.
Day Two
Two websites you will be using all
year!!!

www.nordoniahonorschemistry.wikispac
es.com
 Class website
 Lab manual
 Calendar
 Lecture Notes
 Answer Keys to Homework

www.masteringchemistry.com
 Additional Reviews and assignments
What Is a Measurement?
Quantitative
observation
 Comparison to an
agreed upon
standard
 Every measurement
has a number and a
unit

A Measurement
The unit tells you to what standard you
are comparing your object.
 The number tells you:

1. What multiple of the standard the object
measures.
2. The uncertainty in the measurement.
Scientists have measured the average
global temperature rise over the past
century to be 0.6 °C
°C tells you that the temperature
is being compared to the Celsius
temperature scale.
 0.6 tells you that:

The average temperature rise is 0.6
times the standard unit of 1 degree
Celsius.
2. The confidence in the measurement
is such that we are certain the
measurement is between 0.5 and
0.7 °C.
1.
Scientific Notation

We should all be familiar with this but I
just want to remind you of a few things!!!

S.N. is an easy way to express VERY
large or VERY small numbers

Chemistry most of the time deals with
extremely small number considering we
talk about atoms!
3 parts to S.N.
1.2 X 10
-9
How to Express a number in
Scientific Notation
Move the decimal point to obtain a number
between 1 and 10.
2. Write the result from Step 1 multiplied by
10 raised to the number of places you
moved the decimal
1.
** The exponent is POSITIVE if you moved
the decimal to the LEFT
** The exponent if NEGATIVE if you moved
the decimal to the RIGHT
Practice—Write the Following in Scientific
Notation
123.4
8.0012
145000
0.00234
25.25
0.0123
1.45
0.000 008706
Practice—Write the Following in Standard
Form
2.1 x 103
4.02 x 100
9.66 x 10-4
3.3 x 101
6.04 x 10-2
1.2 x 100
Day Three
Metric System

Group of units used to make any kind of
measurements

Best known for its simpleness
 Why is it so simple?

Used all around the world with scientists
The Standard Units
Scientists generally report results in an
agreed upon International System.
 The SI System

 Aka Système International
Quantity
Length
Mass
Time
Temperature
Unit
meter
kilogram
second
kelvin
Symbol
m
kg
s
K
Some Standard Units in the
Metric System
Quantity
Measured
Name of
Unit
Abbreviation
Mass
gram
g
Length
meter
m
Volume
liter
L
Time
seconds
s
Temperature
Kelvin
K
King Henry Died By Drinking
Chocolate Milk
K
H
D
B
d
c
m
Common Prefixes in the
SI System
Prefix
Symbol
Decimal
Equivalent
Power of 10
1,000,000
Base x 106
1,000
Base x 103
mega-
M
kilo-
k
deci-
d
0.1
Base x 10-1
centi-
c
0.01
Base x 10-2
milli-
m
0.001
Base x 10-3
micro-
m or mc
0.000 001
Base x 10-6
nano-
n
0.000 000 001 Base x 10-9
Tro's "Introductory Chemistry", Chapter 2
23
Let’s Try A Few

125 cm =
____________ mm

0.2568 L = _________ mL

2.56 kg = ________ g
Factor Label
Dimensional Analysis

EASY way to convert from one unit to
another unit!!

WE will be doing this ALL YEAR long!
So you better pay attention now!

UNITS ARE EXTREMELY IMPORTANT
Units
Always write every number with its
associated unit.
 Always include units in your calculations.

 You can do the same kind of operations on
units as you can with numbers.
○ cm × cm = cm2
○ cm + cm = cm
○ cm ÷ cm = 1
 Using units as a guide to problem solving is
called dimensional analysis.
Problem Solving and
Dimensional Analysis
Many problems in chemistry involve using
relationships to convert one unit of measurement
to another.
 Conversion factors are relationships between two
units.

 May be exact or measured.

Conversion factors generated from equivalence
1in
statements.
2.54cm
 e.g., 1 inch = 2.54 cm can give1in
2.54or
cm
Problem Solving and
Dimensional Analysis, Continued


Arrange conversion factors so the starting unit cancels.
 Arrange conversion factor so the starting unit is on
the bottom of the conversion factor.
May string conversion factors.
 So we do not need to know every relationship, as
long as we can find something else the starting and
desired units are related to :
desired unit
start unit 
 desired unit
start unit
related unit desired unit
start unit 

 desired unit
start unit
related unit
Systematic Approach
1.
Write down the given amount and unit.
2.
Write down what you want to find and unit.
3. Write down needed conversion factors or
equations.
Common Units and Their Equivalents
Length
1 kilometer (km)
1 meter (m)
1 meter (m)
1 foot (ft)
1 inch (in.)
=
=
=
=
=
0.6214 mile (mi)
39.37 inches (in.)
1.094 yards (yd)
30.48 centimeters (cm)
2.54 centimeters (cm) exactly
Common Units and Their Equivalents,
Continued
Mass
1 kilogram (km) = 2.205 pounds (lb)
1 pound (lb) = 453.59 grams (g)
1 ounce (oz) = 28.35 (g)
Volume
1 liter (L)
1 liter (L)
1 liter (L)
1 U.S. gallon (gal)
=
=
=
=
1000 milliliters (mL)
1000 cubic centimeters (cm3)
1.057 quarts (qt)
3.785 liters (L)
Lets take a look at one!

I drive 20 miles to school every day. I
want to know how many kilometers I
drive.
Lets Try a Few

125 lb =
________ kg

2.5 gallons = ________ L

3.1 km = _________ miles
Day Four
Exact Numbers vs. Measurements

Sometimes you can determine
an exact value for a quality of an
object.
 Often by counting.
○ Pennies in a pile.
 Sometimes by definition
○ 1 ounce is exactly 1/16th of 1 pound.

Whenever you use an instrument
to compare a quality of an object
to a standard, there is
uncertainty in the comparison.
Reporting Measurements
Measurements are written to indicate the
uncertainty in the measurement.
 The system of writing measurements we
use is called significant figures.
 When writing measurements, all the digits
written are known with certainty except
the last one, which is an estimate.

45.872
Estimated
Certain
Skillbuilder 2.3—Reporting the Right
Number of Digits

A thermometer used to
measure the temperature of
a backyard hot tub is shown
to the right. What is the
temperature reading to the
correct number of digits?
Reporting Numbers with Sig. Figs

When we report numbers in this class
we need to make sure that we do not
report them more specific than they
really are. WHAT???
Volume of a box
Length = 7.12 cm
Width = 2.15 cm
Height = 2.15 cm
How do I know if a number is
significant?
All NONZERO digits are significant
2. Zeros between two nonzero numbers
are significant
3. Trailing zeros are significant
4. Leading zeros are NOT significant,
they are only place holders
5. Zeros at the end of a number but before
a decimal are NOT significant
1.
Lets try a few
0.0035
 1.080
 2371
 2.97 x 105
 100000
 0.500
 58.31

Factor Label (Multi-step)

I went to the Yukon last summer and the
speed limit sign said 105 km/hr. What
was the speed limit in mi/hr?
If I drive a total of 50 miles a day and
my car gets 49 miles/gallon. How
much does it cost me a week to drive
to work? Assuming price for gas is
$2.50/gallon.
A circle has an area of 2,659
cm2. what is its area in square
meters?
Day Five
Significant Figures in
Calculations
ADDITION AND SUBTRACTION

The difference and sum carries the
same number of decimal places as the
quantity carrying the FEWEST decimal
places.

3.449 cm – 0.76 cm =

2.5 cm + 2 cm =
Significant Figures in
Calculations
(MULTIPLICATION AND DIVISION)

The results carries the same number of
significant figures as the factor with the
FEWEST figures.
5.892 cm X 6.10 cm =
Lets take a look back at our
Volume of a Box!!
Volume of a box
Length = 7.12 cm
Width = 2.15 cm
Height = 2.15 cm
Lets Try a Few!

1.01mm x 0.12 cm x 53.51 cm =

56.55 cm x 0.920 cm =

345.0 ml / 120 ml =
Day Six
Day Seven
Day Eight
Density

Ratio of its mass to volume

“How much stuff is in a given space”

Differs from one substance to another
How do I calculate DENSITY?

What about the units?
I have a sample of platinum that has
a mass of 5.84g and it displaces
0.556 cm3 of water. What is the
density?
Lets Try a Few!

The gasoline in an automobile gas tank
has a mass of 60.0 kg and a density of
0.752g /cm3. What is its volume in ml?

A steel cylinder has a volume of 246 cm3
and a density of 7.93 g/cm3. What is its
mass in kg?
Day Nine
Day Ten and Eleven
Day Twelve
Day Thirteen
Day Fourteen