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1. Backpacks/purses in
designated areaThank You!
2. Please take 2 pieces of paper,
a pencil, & syllabus
3. Find the element desk that
matches your element card.
4. Sit in the proper desk.
5. Next, write your name on the
element sheetIll use this for
attendance for today.
EXAMPLE!!
Welcome To Science
Ms. Lara Room A-8
Review Class Syllabus
Learning How To Complete
A Vocabulary Outline
Chemistry
Ch 1 Outline
The following format must be followed in order to receive
full credit:
Write your name and period number at the top right.
Write the title of the vocabulary outline at the top middle
of the page.
Line one will state the number of vocabulary & concepts.
The vocabulary lists will be located at the end of each
chapter. For example, go to page 33 in the textbook (note
next slide)
Name
Period #
Ch 1 Outline (pg 33)
22 Vocabulary + 14 Concepts = 36 Points
Name
Period #
Ch 1 Outline (pg 33)
22 Vocabulary + 14 Concepts = 36 Points
(Page 33)
Note 14
Key Concepts
Note 22
Vocabulary
Name
Period #
Ch 1 Outline (pg 33)
22 Vocabulary + 14 Concepts = 36 Points
Example:
1. analytical chemistry (pg. 8) is the area of study
that focuses on the composition of matter.
1.1 Chemistry
Everything is made of matter & chemistry affects all
aspects of life.
Follow the format below for full credit:
To the left of the vocabulary word/phrase write the
number.
Underline the vocabulary word/phrase, include the
page number.
Summarize the definition. Then repeat the process
for the next vocabulary word/phrase.
Name
Period #
Ch 1 Outline (pg 33)
22 Vocabulary + 14 Concepts = 36 Points
1. analytical chemistry (pg. 8) is the area of study that
focuses on the composition of matter.
Example: pg. 8 in your textbook
1. analytical chemistry (pg. 8) is the area of study
that focuses on the composition of matter.
Summarize the Key Concept bullets (note pg. 33).
Include the subtitles & correct number of bullets.
1.1 Chemistry
Everything is made of matter & chemistry affects
all aspects of life.
Example:
1. analytical chemistry (pg. 8) is the area of
study that focuses on the composition of matter.
1.1 Chemistry
Everything is made of matter & chemistry affects
all aspects of life.
The vocabulary outlines will count as a quiz
grade, no late vocabulary outlines will be
accepted, no exceptions.
Ch 1 Vocabulary Points: 22
Ch 1 Key Concepts Points: 14
= 36 total points
Biology
Ch 1 Outline
The following format must be followed in order to receive
full credit:
Write your name and period number at the top right.
Write the title of the vocabulary outline at the top middle
of the page.
Line one will state the number of vocabulary & concepts.
The vocabulary lists will be located at the end of each
chapter. For example, go to page 30 in the textbook (note
next slide)Name
Period #
Ch 1 Outline (pg 30)
24 Vocabulary + 7 Concepts = 31 Points
Name
Period #
Ch 1 Outline (pg 30)
24 Vocabulary + 7 Concepts = 31 Points
(Page 30)
Note 7 total
Key Concepts
Note 24 total
Vocabulary
Summarize the Key Concept bullets (note pg. 30). Include
the subtitles & correct number of bullets.
Name
Period #
Ch 1 Outline (pg 30)
24 Vocabulary + 7 Concepts = 31 Points
1.1 What Is Science?
The goal of science is to investigate and understand &
explain the natural world and to make useful predictions.
Follow the format below for full credit:
To the left of the vocabulary word/phrase write the
number, underline the vocabulary word/phrase,
(include the page number), Summarize the
definition. Then repeat the process. NamePeriod #
Ch 1 Outline (pg 30)
24 Vocabulary + 7 Concepts = 31 Points
1.1 What Is Science?
The goal of science is to investigate and understand &
explain the natural world and to make useful predictions.
1. science (pg. 3) an organized way of using evidence to
learn about the natural world.
Example: pg. 3 in your textbook
1. science (pg. 3) an organized way of using
evidence to learn about the natural world.
The vocabulary outlines will count as a quiz
grade, no late vocabulary outlines will be
accepted, no exceptions.
Ch 1 Vocabulary Points: 24
Ch 1 Key Concepts Points: 7
= 31 total points
Chemistry
Ch 2 Outline
(Page 57)
Note: Key
Concepts
Note:
Vocabulary
The following format must be followed in
order to receive full credit:
To the left of the vocabulary word/phrase write
the number.
Next, Underline the vocabulary word/phrase,
include the page number to find the definition.
Find the definition in the textbook & write the
definition next to the vocabulary word/phrase.
Then repeat the process for the next vocabulary
word/phrase.
Example: pg. 48 in your textbook
1. Chemical Change (pg. 48): a change that
produces matter with a different composition.
Once you are finished with the vocabulary list,
summarize the Key Concepts (note pg. 57).
The vocabulary outlines will count as a quiz
grade, no late vocabulary outlines will be
accepted, no exceptions.
Ch 2 Points: 28 Vocab. + 12 Key Concepts
= 40 total points
Ch 10.3 Points: 1 Vocab. + 3 Key Concepts
= 4 total points
If you get finished with an assignment early
during class, finish the vocabulary outline by
using the online textbook.
Ch 1.1 and 1.2
What Is Chemistry?
&
Who Is Ira Remsen
Objectives:
Define chemistry.
Identify possible clues that a chemical
change has taken place.
Relate pure chemistry to applied chemistry.
Chemistry is the study of matter and the changes
that it can undergo.
Matter is anything that has mass and occupies
space.
Chemistry is something that can be observed.
In lab, how will you know if matter is changed,
(if a chemical reaction occurs)?
An observation is the act of making and recording
a measurement. There are two types of
observations:
Qualitative data describes a non-number observation
(Quality)
Quantitative data describes number observations
(Quantity)
Label each data as qualitative or quantitative A beaker weighs 6.6 g, Sugar crystals are white & shiny,
Strontium fireworks burn red, the beaker gets hot
Write down as many observations that you can make
during the reaction of copper in nitric acid.
Evidence of a Chemical Reaction
Color change
Gas bubbles
Heat (exothermic)
Cooling (endothermic)
Flames/Light
Precipitate (ppt)
New odor
Types of Reactions:Precipitation (ppt) Exothermic & Light
Compare your observations to those of Ira Remsens
Ira was a well known Chemist (1846-1927) and Co-
discoverer of saccharin (Sweet N Low), He founded the
chemistry department at Johns Hopkins University
He is also famous for his story of watching nitric acid
acting upon copper while waiting in a doctors office.
http://www.eagan.k12.mn.us/fletcher/acn/flash/nitric_copper.html
http://www.eagan.k12.mn.us/fletcher/acn/flash/nitric_copper.html
Color change
Gas bubbles
Heat (exothermic)
Cooling (endothermic)
Flames/Light
Precipitate (ppt)
New odor
As you listen to the Ira Remsen story, place
check marks next to the chemical changes that
you observe.
Ira Remsen:
Copper & Nitric Acid
Chemistry Areas of Study
Chemistry affects all aspects of life because living
and nonliving things are made of matter.
Some chemists enjoy doing research simply to
pursue chemical knowledge for its own sake. This
type of research is called pure chemistry, (the
chemist doesnt expect that there will be any
immediate practical use for the knowledge).
Ira Remsen was a chemist who enjoyed pursuing
pure chemistry
Most chemists do research that is designed to
answer a specific question this is known as
Applied chemistry. This research is directed
toward a practical goal or application. In practice,
pure chemistry and applied chemistry are often
linked.
Remember, Ira was a great observer, this is how
his laboratory discovered Saccharine (SweetN
Low).
Saccharine is Latin for sugary.
Ira & Discovery Of Saccharin
Cornell Question Guide
Explain why chemistry affects all aspects of
life.
Who is Ira Remsen and what discovery did
he make that we use in every day life?
How are chemistry and matter related.
Name 3 type of chemical changes
(reactions) that we will look for during an
experiment.
Bell Ringer:
Define Chemistry
List 3 types of observations indicating that
chemistry is occurring:
1.
2.
3.
Ch 1.1 and 1.2
What Is Chemistry?
Ch 1.3
Scientific Methods
Objectives:
Define chemistry.
Identify possible clues that a chemical
change has taken place.
Identify the steps of the scientific method.
Chemistry is the study of matter and the changes
that it can undergo.
Matter is anything that has mass and occupies
space.
Chemistry is something that can be observed.
In lab, how will you know if matter is changed,
(if a chemical reaction occurs)?
Evidence of a Chemical Reaction
Color change
Gas bubbles
Heat (exothermic)
Cooling (endothermic)
Flames/Light
Precipitate (ppt)
New odor
Types of Reactions:Precipitation (ppt) Exothermic & Light
Ch 1.3
Scientific Methods
Scientific Methods Scientific methods are used by scientists to answer
questions and solve problems.
Below is a general process, not a checklist. A
scientist can begin investigating at any step within
the process but must describe their methods. That is
the purpose for a lab report.
Observations Observing The first step toward scientific discovery often
takes place when a scientist observes something no one has noticed before.
Qualitative data describes an observation (Quality)
Quantitative data use numbers (Quantity)
Label each data as qualitative or quantitative:
A beaker weighs 6.6 g, Sugar crystals are white & shiny, Fireworks are colorful
Hypothesis
Making a hypothesis: A hypothesis is a testable
explanation or answer to a question.
Experiments
A Hypothesis is meaningless unless there's data to support it.
Experiment is a set of controlled observations that test the
hypothesis.
One or more experiments are carefully planned in order to
change/test one variable at a time. Variables are quantities
that can have more than one value. There are 2 types of
variables:
Independent variable is that which you plan to change.
Dependent variables change in response to a change in the
independent variable.
Conclusion
Collecting data: Investigations and experiments
test a hypothesis. Data must be thoroughly
analyzed to determine whether the hypothesis was
supported or disproved. From the results, a
conclusion can be formed.
Publishing
Publishing results: Results of an investigation
are useful only if they are made available to other
scientists for a peer review. Many scientists
published their observations in scientific
literature.
Scientists will analyze the procedure, examine
the evidence, identify faulty reasoning, point out
statements that go beyond the evidence, and
suggest alternative explanations for the same
observations.
Forming a theory: A theory is a hypothesis that is
supported by a large body of scientific evidence over time.
Revising a theory: A theory is a hypothesis supported by
many experiments, but still subject to changes.
Scientific Law is the summary of accepted facts of nature.
Theory and Scientific Law
Cornell Guide
Chapter 1.3
Why should a hypothesis be developed
before experiments take place?
Give 2 qualitative and 2 quantitative data
types.
Name the 2 types of variables.
What is the difference between a theory and
a scientific law?
Reaction In A BagGo To
OneNote
How To Use Clickers
To turn on/off.
You will have to enter the
Version of your exam.
If you are A Version enter:
1 A
If you are B Version enter:
2 B
To Delete an answer.
To Scroll through
answers.
To Enter an answer.
Ch 2.3 & 3.4 (Glencoe)
Elements & Compounds
Objectives
Explain the difference between an element
and a compound.
Identify the chemical symbols of elements,
and name elements.
Ch 2.3 & 3.4 (Glencoe)
Elements & Compounds
Do you see Chemistry in this picture? Most people
say no, they dont. Chemistry cant be seen.
Therefore, Scientists represent atoms by using
different colored circles, called a model.
Models are tools that scientists use.
Cornell Questions?
What is the difference between matter,
atoms, and elements?
Matter is composed of tiny particles called
atoms.
Substances which cannot be broken down into
simpler substances by chemical reactions are
called atoms.
Not all atoms are alike, all matter is composed of
about 100 different types of atoms called
elements.
Each element is unique. Elements have their own
physical and chemical characteristics.
Below is an example of each element in model
format. An element in model form is a single,
colored circle.
Elements are organized in a table called the periodic
table of the elements
An element is identified by
its symbol; this consists of
one or two letters, usually
derived from its name:
C = Carbon
Co = Cobalt
Sometimes the element
symbol does not match the
element name. This occurs
because the Latin name is
sometimes used, i.e.
Cu = Copper (Cuprum)
If you look at the table below, other languages
(other than Latin) are used for element symbols.
Cornell Question?
What is the most important tool that a
scientist uses?
(Watch the video)
Cornell Questions?
How is each element different from
eachother?
How are the elements created?
How are the elements heavier than iron
(Fe) created?
(Watch the video)
Each element is
different from other
elements because it
has a different number
of protons.
As a result each
element has unique
physical & chemical
properties.
Elements are organized in the periodic table by the Blue
Number called the atomic number.
The atomic number is the number of protons in the
element.
Question#1: What is the symbol of the element
phosphorus & number of protons?
Question#2: What is the symbol of the element potassium
& number of protons?
Question#3: What is the symbol of the element Krypton 7
number of protons?
How Is The
Periodic Table Organized?
Take Out Blank Periodic Table
Label Groups
Going From Top To Bottom
Groups/Families
Elements with similar
chemical and physical
properties are in the
same column
Columns are called
groups or families
Label Periods
Going From Left To Right
Rows are called periods
Each period shows the pattern of properties repeated in the next period
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Metals, Metalloids, Nonmetals
Metallic Character
Metals Metalloids Nonmetals
Malleable & ductile
Shiny, lustrous
Also known as semi-
metals
Brittle in solid state
Good conductors of heat
and electricity
Show some metal and
some nonmetal properties
Poor conductors of heat
and electricity
(insulators)
Cornell Questions?
Weve been discussing how elements have
different physical and chemical properties.
(Watch the video)
List 3 physical properties:
List 3 chemical properties:
Physical & Chemical Changes
Cornell Guide
Chapter 2.3
Explain how an element symbol is represented.
Write the chemical symbol for each element:
Hydrogen, silver, helium, oxygen, gold
Name the chemical elements:
Cl, Fe, B, Be, Br
What is the difference between an atom and
element?
Practice: Protons & Elements
Practice: Element Name Word Search
Ch 3.4 (Glencoe)
Pure SubstancesObjectives:
Categorize a sample of matter as a substance or
a mixture.
Ch 3.4 (Glencoe)
Pure Substances DIVIDE YOUR CORNELL NOTES PAGE
INTO 3 COLUMNS
Elements Compounds Mixtures
Review:
Elements
Each element is unique. Elements have their own
physical and chemical characteristics.
Below is an example of each element in model format.
An element in model form is a single, colored circle.
A model is a visual of experimental data. Chemists use
models to represent matter, such as elements
Pure substances have fixed
properties:
Fe is a metal and magnetic
S is a nonmetal and not
magnetic
Elements are pure substances
Elements At
The Atomic
Level
Pure substances have a fixed
constant composition.
Elements are all the same,
thus a pure substance.
http://www.privatehand.com/flash/elements.html
The Element Song
http://www.privatehand.com/flash/elements.html
Polyatomic Elements
Poly (many) atomic (atoms) Polyatomicelements consist of several like atoms naturally bonded together
Memorize these 7 Diatomic elements:
H2, N2 , O2, F2, Cl2 Br2, I2
Remember
7th Heaven Rule
On Your Periodic Table
Color Code Those 7 Elements
Diatomic Elements
At The Atomic Level
Diatomic elements are pure substances
Compounds
Most substances are chemical combinations of
elements called compounds.
Below are some models of different compounds.
Compounds are more than one colored circle
connected by a stick known as a bond.
Compounds
Are Pure Substances
Compounds At The
Atomic Level
Compounds also have fixed
compositions, thus compounds
are pure substances.
Compounds are formed by a
chemical process.
The new compound has new
properties different from the
original elements that formed it.
Cornell Questions
1. Define pure substance:
2. List 3 examples of a pure substance:
3. Is carbon dioxide (CO2) a pure substance?
4. Explain why or why not:
Cornell Qs Continued
5. Define element:
6. Define compound:
7. How is it possible to distinguish an element from
a compound?
8. Name the elements contained in the following
compounds:
a. sodium chloride (NaCl) =
b. ethanol (C2H6O) =
c. ammonia (NH3) =
d. bromine (Br2) =
Complete Practice Problems:
Protons, Elements, Compounds, Mixtures
Only complete the first page
Review
Elements are organized in the periodic table by the Blue
Number called the atomic number.
The atomic number is the number of protons in the
element.
What are the models below?
Compounds or elements?
Pure substances or mixtures?
Ch 3.4 (Glencoe)
Mixtures
A mixtures is composed of two
or more pure substances
physically combined
Mixtures are separated by a
Physical process
In this case Fe and S are mixed
and separated physically with a
magnet
Mixture At The Atomic Level
Cornell Questions?
What is the color of the elements:
Iron (Fe) Fillings:
Sulfur (S) Powder:
How was the mixture of Iron and sulfur
physically separated?
How does one know if iron and sulfur had reacted
chemically instead of physically mixed?
Mixtures & Compounds Review
Cornell Questions
A)Element B)Compound
C)Mixture D) Pure Substance
________________
________________
________________
A)Element B)Compound
C)Mixture D) Pure Substance
_________________
_________________
_________________
Practice Problems To Complete:
Models of Elements, Compounds, &
Mixtures
3.4
Formulas of Elements &
Compounds
Objective:
Chemical symbols make it easy to write the
formulas of chemical compounds.
Review
Review: What are the models below?
Diatomic elements, compounds, or elements?
Name the atomic model below:
Element, Diatomic Element or Compound
Then classify:
Pure Substance or Mixture
________________
________________
________________
Instead of drawing models to represent
elements and compounds, it is more practical
to use the element symbols.
Formulas can be a single element or a
combination of element symbols to represent a
compound.
Note the next slide
1. H2
2. Mg
3. CO
4. Co
5. CO2
Are the formulas provided elements, compounds, or diatomic
elements?
If an element, write the name.
If compounds determine the number of elements in each compound
If diatomic element state diatomic element.
Answer
The answers are
Diatomic Element: H = 2
Element: Magnesium
Compound: C = 1 O = 1
Element: Cobalt
1. H2
2. Mg
3. CO
4. Co
5. CO2 Compound: C = 1 O = 2
Question
1. (NH4)2SO4
2. Na3PO4
3. Fe(NO2)3
4. CH3COOH
These formulas are compounds.
Determine the number of elements in each compound.
Answer
1. (NH4)2SO4 N = 2 H = 8 S = 1 O =4
2. Na3PO4
4. Fe(NO2)3
5. CH3COOH
Answers Are The Following:
1. (NH4)2SO4 N = 2 H = 8 S = 1 O =4
2. Na3PO4 Na = 3 P = 1 O = 4
4. Fe(NO2)3
5. CH3COOH
Answers Are The Following:
1. (NH4)2SO4 N = 2 H = 8 S = 1 O =4
2. Na3PO4 Na = 3 P = 1 O = 4
4. Fe(NO2)3 Fe = 1 N = 3 O = 6
5. CH3COOH
Answers Are The Following:
1. (NH4)2SO4 N = 2 H = 8 S = 1 O =4
2. Na3PO4 Na = 3 P = 1 O = 4
4. Fe(NO2)3 Fe = 1 N = 3 O = 6
5. CH3COOH C = 2 H= 4 O = 2
Answers Are The Following:
Element Compound or Diatomic Element?
Na
Na2O Element: Name of Element
NaHCO3
CaO
Ca(HCO3)2 Compound: Elements In Formula
Al
Al2O3
Al(HCO3)3 Diatomic Element
H2
O2
Practice Problems To Complete:
Element, Diatomic, Compound
Ch 10.3
Calculating amu
Objective:
Describe how to calculate the amu of a
compound.
Calculating AMU
Next, lets determine the mass of each atom.
As we learned, there are different types of
atoms known as elements.
Each element has a different mass and it is
called its amu
atomic mass units
Another name for amu is molar mass (Ch 6.4)
or molecular weight.
Molar mass is obtained by summing the masses
of the component atoms.
The amu is the red number in your periodic table
Amu is also known as its atomic weight
To calculate amu, go to 2 decimal placesLets look at a few
Go to 2 decimal places for AMU, lets look at a few:
N = O = K =
H = F = C =
Na = Li = Cl =
1. (NH4)2SO4 N = 2 H = 8 S = 1 O =4
2. Na3PO4 Na = 3 P = 1 O = 4
3. Fe(NO2)3 Fe = 1 N = 3 O = 6
4. CH3COOH C = 2 H= 4 O = 2
Remember This???
How Would We Determine The
amu Of CO2?First determine the number of atoms in the formula:
C =
O =
How Would We Determine The
amu Of CO2First determine the number of elements in the formula:
C = 1 atom
O = 2 atoms
Next, find the amu for each element
(go to 2 decimal places):
C = 1 atom x 12.01 amu
O = 2 atoms x 16.00 amu
Finally, multiply the number of atoms by amu
And find the total amu:
C = 1 atom x 12.01 amu = 12.01 amu
O = 2 atoms x 16.00 amu = 32.00 amu
Finally, multiply the number of atoms by amu
And find the total amu:
C = 1 atom x 12.01 amu = 12.01 amu
O = 2 atoms x 16.00 amu = 32.00 amu
CO2 total amu = 44.01 amu
How would we determine the amu of windex,
NH3?
Amu of NH3:
N = 1 atom
H = 3 atoms
Amu of NH3:
N = 1 atom x 14.01 amu
H = 3 atoms x 1.01 amu
Amu of NH3:
N = 1 atom x 14.01 amu = 14.01 amu
H = 3 atoms x 1.01 amu = 3.03 amu
Amu of NH3:
N = 1 atom x 14.01 amu = 14.01 amu
H = 3 atoms x 1.01 amu = 3.03 amu
total amu = 17.04 amu
or 17.04 molar mass
Lets practice another one
Calculate amu of butane:
C4H10
Practice Problems To Complete:
AMU Calculations ONLY pg. 2
Lab Partner Quiz
Name the atomic model below:
Element, Diatomic Element or Compound
Then classify:
Pure Substance or Mixture
________________
________________
________________
Go to 2 decimal places for AMU:
N = O = K =
1. (NH4)2SO4
2. Na3PO4
Calculate the AMU of the compounds below:
Ch 10.3
Percentage Composition
Using amu
Objective:
Describe how to calculate the percent
composition of an element in a compound.
How Can We Calculate
% Boys and % Girls In The Class?
To find percent of anything it is simply
this formula:
What You Want x 100%
The Total
What is the % Boys?
What is the % Girls?
Use amus for calculating Percentage Composition:
Percent composition = Element amu x 100%
Compound amu
How Would We Determine The
%C and %O
First determine the number of atoms in the formula:
C =
O =
First determine the number of elements in the formula:
C = 1 atom
O = 2 atoms
Next, find the amu for each element
(go to 2 decimal places):
C = 1 atom x 12.01 amu
O = 2 atoms x 16.00 amu
Finally, multiply the number of atoms by amu
And find the total amu:
C = 1 atom x 12.01 amu = 12.01 amu
O = 2 atoms x 16.00 amu = 32.00 amu
Finally, multiply the number of atoms by amu
And find the total amu:
C = 1 atom x 12.01 amu = 12.01 amu
O = 2 atoms x 16.00 amu = 32.00 amu
CO2 total amu = 44.01 amu
Percent composition = Element amu x 100%
Compound amu
C = 1 atom x 12.01 amu = 12.01 amu/44.01 x100%
O = 2 atoms x 16.00 amu = 32.00 amu/44.01x 100%
CO2 total amu = 44.01 amu
% C = 27.29%
% O = 72.71%
(This adds up to 100%)
Look At Page 307:
What is the % N to % H of Windex, which is
NH3 (ammonia)?
Use amus for calculating Percentage Composition:
Percent composition = Element amu x 100%
Compound amu
First determine the amu for the
formula NH3:
How would we determine the amu of windex,
NH3?
Amu of NH3:
N = 1 atom
H = 3 atoms
Amu of NH3:
N = 1 atom x 14.01 amu
H = 3 atoms x 1.01 amu
Amu of NH3:
N = 1 atom x 14.01 amu = 14.01 amu
H = 3 atoms x 1.01 amu = 3.03 amu
Amu of NH3:
N = 1 atom x 14.01 amu= 14.01/17.04 x 100%
H = 3 atoms x 1.01 amu =3.03/17.04 x 100%
total amu = 17.04 amu
% N = 82.22%
% H = 17.78%
(Adds up to 100%)
The percentages may not always total to 100% due to rounding,
for example if you go to 1 decimal spot
82.2% N
+ 17.7% H
99.9 % total
But if you go to 2 decimal spots you get closer to 100%
82.21% N
+ 17.79% H
100.00 % total
Overall your numbers should
add up close to 100%
Lets practice another one
Calculate Percentage composition of
butane C4H10:
Practice Problems To Complete:
% Using AMU
Ch 10.3
Calculating % Composition By
Given Masses
Objective:
Describe how to calculate the percent by
mass of an element in a compound.
Ch 10.3
Calculating % Composition By
Given Masses
The Law of Definite Proportions states that a
compound is always composed of the same
elements in the same proportion by mass.
The mass of the compound is equal to the sum of
all the masses of the elements.
Percent by mass:
% Composition = Part Element Mass x 100%
Total Compound Mass
A sample of butane (C4H10)--lighter fluid--
contains 288 g carbon and 60 g hydrogen.
Find %C and %H in butane
%C =
%H =
A sample of butane (C4H10)--lighter fluid
contains 288 g carbon and 60 g hydrogen.
First find the total
288 g C + 60 g H = 348 g
Part Part Total
Next, calculate the percent of each element:
Percent composition = Part x 100%
Total
288 g C + 60 g H = 348 g
Part Part Total
Can you figure it out?
Next, calculate the percent of each element:
Percent composition = Part x 100%
Total
288 g C + 60 g H = 348 g
Part Part Total
288 g C (C part) x 100 % = 82.8 % C
348 g (Total)
60 g H (H part) x 100% = 17.2 % H
348 g (Total) + ---------------
100.0 %
Percents should add up close to 100%
Now you and your lab partner try this one
What is the percentage composition of
carbon and oxygen in a compound, that contains
40.8 g of carbon and 54.4 g of oxygen.
% C = ?
% O = ?
40.8 g of carbon + 54.4 g of Oxygen = 95.2 g total
Percent composition = Part x 100%
Total
40.8 g of carbon x 100 % = 42.86% Carbon
95.2 g total
54.4 g of Oxygen x 100% = 57.14% Oxygen
95.2 g total
Practice Problems To Complete:
% Composition By Given Mass
Ch 2.3
Uncertainty In Data
Objective: Identify and apply measurement
techniques and consider possible effects of
measurement errors.
Ch 2.3
Uncertainty In Data
Accuracy
Accuracy refers to how close an experimental
measurement is to some accepted value
(theoretical value), well use % error:
(NOTE: Use Absolute Value)
% error = exp value accepted value x 100%
accepted value
In lab Josh finds the boiling point of rubbing
alcohol to be 75 degrees. He looks online at the
Handbook of Chemistry & Physics that the
boiling point should be 80. degrees.
Calculate the % Error:
% error = exp value accepted value x 100%
accepted value
Jill weighs an element on a balance. The element
has a mass of 24.3 grams. The periodic table has
the accepted value to be 25.7 grams.
Calculate the % Error:
% error = exp value accepted value x 100%
accepted value
The density of water at 4 degrees is 1.00 g/mL.
John experimentally found the density to be 1.08
g/mL.
Calculate the % Error:
% error = exp value accepted value x 100%
accepted value
Ch 10.3
Calculating the AMU Of A
Hydrate Crystal
Objective:
Describe how to calculate the AMU of a
hydrate crystal.
Ch 10.3
Calculating the AMU Of A
Hydrate Crystal
Ch 10.3
Calculating the % Water Of A
Hydrate Crystal
Objective:
Describe how to calculate the percent water
of a hydrate crystal.
Ch 10.3
Calculating the % Water Of A
Hydrate Crystal
Lab Power Point
Hydrate Crystals
Title: % Water In A Hydrate
Purpose: Analysis of the % water of an unknown
crystal & to I.D. the hydrate from a list of
possible calculated unknowns.
Pre-Lab Notes:
Hydrate Definitions
Hydrates
A compound that is hydrated is called a hydratesince they form solids that include water in their crystal structure.
Compounds that contain water molecules as part of their
crystal structure are called hydrates.
Heating a hydrate drives off the water molecules, and
the solid that remains behind is called anhydrous,
meaning without water.
By simply heating the solid, water can be driven from a
hydrate to leave an anhydrous compound.
Notice the color difference of:
Anhydrous crystals copper (II) sulfate
NOTE: Black material is Copper II Oxide
Hydrate crystals copper (II) sulfate
Hydrate AMU Calculation
CuSO4 5 H2O
When calculating the molar mass
add the AMU of water. The dot
indicates 5 waters, therefore add
the salt AMU + water AMU
CuSO4 5 H2O
Calculate below:
CuSO4 5 H2O
When calculating the molar mass
add the AMU of water. The dot
indicates 5 waters, therefore add
the salt AMU + water AMU
CuSO4 5 H2O
Calculate below:
% Water Calculation
Practice Obtaining
Acceptable Value
How to calculate Percentage Water:
% water = # of waters amu x 100%
hydrate crystals amu
% water = 5 H2O amu x 100%
CuSO4 5 H2O amu
Practice Problems:
AMU of Hydrates
Use AMU of Hydrates to practice
calculating % water in each hydrate
crystal
Practice Calculating % Water: Cd(NO3)2 4 H2O
NaClO4 1 H2O
Ba(OH)2 8 H2O
NiCl2 6 H2O
Practice Obtaining Experimental
Values
When you find the mass
of substances that you
heat, you have to weigh
the containerWhy
should one do this?
Calculate % Water
experimentally using
the next slide and
video
Lets copy the sample data tables below (were still in pre-
lab notes of the lab)
#1 Mass empty crucible: ____________________________
#2 Mass crucible+hydrate salt (before heating): __________
#3 Mass of crucible+anhydrate (after heating): __________
Lets watch the experiment:
#1 Mass empty crucible:
#2 Mass crucible+hydrate salt (before heating):
#3 Mass of crucible+anhydrate (after heating):
#1 Mass empty crucible: 20.057 g
#2 Mass crucible+hydrate salt (before heating): 45.551 g
#3 Mass of test tube+anhydrate (after heating): 38.547 g
Copy the data tables below and calculate (show work):
Calculate the mass of the hydrate (#2 - #1):
Calculate the mass of water lost during heating (#2 - #3):
Calculate % water in the hydrate (Experimental Number);
g water x 100%
g hydrate crystal
#1 Mass empty crucible: 20.057 g
#2 Mass crucible+hydrate salt (before heating): 45.551 g
#3 Mass of test tube+anhydrate (after heating): 38.547 g
Calculate the mass of the hydrate (#2 - #1):
45.551 g
- 20.057 g
25.494 g Blue Hydrate Salt
Calculate the mass of water lost during heating (#2 - #3):
45.551 g
- 38.547 g
7.004 g of Water Lost
Calculate the percent water in the hydrate g of water x 100% =
g of Hydrate Salt
7.004 g of Water Lost X 100% = 27.47% Water
25.494 g Blue Hydrate Salt Experimental Value
How Would You Calculate
% Error??
Accepted value (theoretical value calculated on
paper using the periodic table).
Experimental value is found from data in the lab.
% error = exp value accepted value x 100%
accepted value
check next slide
Accepted % Water (using periodic table):
90.10 g water x 100% = 36.08 %
249.72 g Hydrate accepted value
% error = exp value accepted value x 100%
accepted value
Experimental % Water (using data):7.004 g of Water Lost X 100% = 27.47% Water
25.494 g Blue Hydrate Salt Experimental Value
Procedure: (Use OneNote PDF)
Review How To Use
An Electric Balance
Practice Problems:
AMU of Hydrates
Use AMU of Hydrates to practice
calculating % water in each hydrate
crystal
Practice Calculating % Water: Cd(NO3)2 4 H2O
NaClO4 1 H2O
Ba(OH)2 8 H2O
NiCl2 6 H2O
Ch 2.3
Uncertainty In Data
Objective: Identify and apply measurement
techniques and consider possible effects of
measurement errors.
Accuracy
Accuracy refers to how close an experimental
measurement is to some accepted value
(theoretical value), well use % error:
% error = exp value accepted value x 100%
accepted value
In lab Josh finds the boiling point of rubbing
alcohol to be 75 degrees. He looks online & the
boiling point should be 80 degrees.
Calculate the % Error:
% error = exp value accepted value x 100%
accepted value
Jill weighs an element on a balance. The element
has a mass of 24.3 grams. The periodic table has
the accepted value to be 25.7 grams.
Calculate the % Error:
% error = exp value accepted value x 100%
accepted value
The density of water at 4 degrees is 1.00 g/mL.
John experimentally found the density to be 1.08
g/mL.
Calculate the % Error:
% error = exp value accepted value x 100%
accepted value
If you remember Accuracy refers to how close
an experimental measurement is to some
accepted value (theoretical value), well use %
error:
% error = exp value accepted value x 100%
accepted value
CuSO4 5 H2O Recently we calculated the amu ofCopper II Sulfate PentaHydrate
theoretically the amu is the
following:
CuSO4 5 H2O amu = 249.69
CuSO4 5 H2O Calculate % Water theoretically using the amu:
CuSO4 5 H2O amu = 249.69
90.10 g water x 100% = 36.08 %
249.69 g Hydrate accepted value
Chemical Changes
Chemical reactions are chemical changes. It involves
the rearrangement of atoms to produce new substances
and chemical changes.
How do we know if matter is
changing (chemistry occurring)?
Observations to watch for:
Permanent new state change (e.g. liquids to solid, ppt)
Formation of gas bubbles
Formation of light or flames
Temperature change (e.g. gets colder or hotter)
A color change
A new odor
The first video will
illustrate how O2 gas
and H2 react to form
water (chemical
reaction)
The second video will
show how we can use
this type of reactions
energy as a fuel
source for the Space
Shuttle
The
Law Of Conservation
The Law of Conservation of Mass states that atoms are neither created nor destroyed
Atoms are merely rearranged to create something new, with new chemical and physical properties
Lets observe the reaction movie on the next
slide.
Is the law of conservation of mass shown?
Note the beakers before and after
Id say the law of conservation of mass is shown
Parts Of A Chemical Equation
Reactants are the chemicals reacting
Products are the chemicals produced
Use the + sign to separate chemicals
Use the yield sign
(Do NOT Use = equals sign)
To obey the Law of Conservation it must be balanced by adding coefficients mass of reactants = mass of products
We will learn to balance equations later.
Ch 2.2
Changes In Matter
Objective:
Three states of matter are solid, liquid, and gas
Matter is the part of the universe that has mass
and volume and exists in three phases:
Solid
Liquid
Gas
Phase changes
are NOT
chemical changes!
Solid:
Does not flow easily
Definite (fixed) shape
Definite (fixed) volume
Particles are close together
(thus not easily compressible)
Liquid:
Flows easily.
Definite shape (takes the shape
of any container)
Definite volume
Little space between particles
(thus not easily compressible)
Gas:
Flows easily
Takes the shape of the
container
Fills the volume of the
container
Particles are very far apart
(thus, easily compressible)
Physical Changes
Physical Changes The process of boiling and freezing causes
physical changes. I.g.
water changes form but
still remains the H2O
compound.
The change is in the
form of a substance &
not its chemical
composition.
H2O (s) = solid water
H2O (l) = liquid water
H2O (g) = gas water
(water vapor)
2.2
Mixtures Of Matter
There are two types of mixtures
Mixtures can be Homogeneous or
Heterogeneous
Homogeneous Mixtures
Homogeneous mixtures (a uniform
mixture) has a composition that is the
same throughout. It is also known as a
solution.
The solute is usually the
smaller number and it gets
dissolved
The solvent is usually the
bigger number and does
the dissolving
The homogeneous
mixture, the solution
consists of the solute and
solvent thoroughly mixed.
Solute + Solvent = Solution
2.18 g
Solute
55.50 g
Solvent
Solution
Remember:
Solute + Solvent = Solution
To finding % mass in solution:
Solute mass x 100%
Solution mass
2.18 g
Solute
+ 55.50 g
Solvent__
57.68g2.18 g x 100%
2.18 g +55.50g
2.18 g x 100% = 3.78%
57.68 g
The next video segment will show how a
solution is made
Types of Solutions
Solutions dont have to be a solid solute dissolved
in an liquid solvent.
Gaseous solutions:
For example Air =
80% N2 and 20% O2
Solid Solutions:
For example door knobs =
67% Cu and 33 % Zn
Solutions which consist of a gas solute dissolved
in a liquid solvent:
carbonated drinks =
CO2 and H2O
Video Review: Solutions
Heterogeneous Mixtures
Heterogeneous mixtures (are non-uniform mixtures)
they have different composition and properties and
several components can be distinguished from one
another
This usually occurs when a solute is not soluble in a
solvent.
Separation of Mixtures
Separation of Mixtures
Many different methods can be used to separate
the components of a mixture from one another
This involves a physical change
NO chemical reaction is needed, substances are
NOT bonded, just physically combined
Here are a couple of methods that you may carry
out in the laboratory
Decanting separates a liquid from a solid
Filtration separates a liquid from a solid as well
For example, filtering sand from saltwater
Distillation Distillation:
separates a solution
by different boiling
points
Water is separated
from the salt by
heating the solution,
minerals are left
behind and the
steam is condensed
to pure water.
This is how distilled
water is made
http://adventure.howstuffworks.com/27665-g-
word-water-desalination-video.htm
Watch this video segment about distilling
dirty water to produce clean water
http://adventure.howstuffworks.com/27665-g-word-water-desalination-video.htm
Paper Chromatography Chromatography:
separates a solution of
different colors
Here a strip of porous
paper, such as filter
paper, is dipped into a
liquid, which travels
up the paper, like a
wick, and the ink
mixture separates into
its component colors
For chromatography the
solute is the dye and the
solvent is the water.
You need to make sure
that the solute and
solvent are chemically
similar so that the
process of
chromatography will
work This is called
solubility
Review: Separating Mixtures