chapter 1
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Chapter 1. Matter and Energy. What is Chemistry. Chemistry is the study of matter and its changes. What is Matter?. Matter is anything that occupies space and has weight. Examples of Matter. Pens and pencils Paper Students Desks Cars Airplanes. Is Air Matter?. - PowerPoint PPT PresentationTRANSCRIPT
Chapter 1Matter and Energy
What is Chemistry
Chemistry is the study of matter and its changes
What is Matter?
Matter is anything that occupies space and has weight.
Examples of Matter
• Pens and pencils
• Paper
• Students
• Desks
• Cars
• Airplanes
Is Air Matter?
Air would be matter if it takes up space and has weight.
Is Air Matter?
Air would be matter if it takes up space and has weight.
Does it?
Is Air Matter?
Air would be matter if it takes up space and has weight.
Does it?
The space that air takes up is called the atmosphere.
Does air have weight?
Is Air Matter?
Air would be matter if it takes up space and has weight.
Does it?
The space that air takes up is called the atmosphere.
Does air have weight?
Yes air does have weight, if not, then it would flow into outer space.
Is Air Matter?
Air would be matter if it takes up space and has weight.Does it?The space that air takes up is called the atmosphere.Does air have weight?Yes air does have weight, if not, then it would flow into outer space. One liter of air weighs 1.29 grams.
What are Changes?In the study of chemistry we talk about two different kinds of changes, physical and chemical
What are Changes?In the study of chemistry we talk about two different kinds of changes, physical and chemical
Physical change is a change to matter so that the identity is not altered; i.e. taste, smell….
What are Changes?In the study of chemistry we talk about two different kinds of changes, physical and chemical
Physical change is a change to matter so that the identity is not altered; i.e. taste, smell….
Chemical change is a change to matter so that its identity is changed; i.e. different smell, color, taste.
Examples of Physical Change
• Tearing paper; starts out paper and ends as paper
• Folding paper ; starts out paper and ends as paper
• Melting of ice ; starts out water and ends as water
• Evaporation of water ; starts out water and ends as water
Examples of Chemical Change• Wood burning; starts out as wood ends up
as smoke and ashes, different smell and taste, right?
• Steel rusting; starts out as steel ends up as rust, different smell and taste
• Healing of a wound; starts out a blood ends up as scar tissue, different color, taste and smell
Matter Continued
Is everything matter?
Matter Continued
Is everything matter? No, not everything we can think of has weight and takes up space.
Matter Continued
Is everything matter? No, not everything we can think of has weight and takes up space.
For example personality!
Matter Continued
Is everything matter? No, not everything we can think of has weight and takes up space.
For example personality! One might argue that personality takes up the space of ones brain or person, but…
Matter Continued
Is everything matter? No, not everything we can think of has weight and takes up space.
For example personality! One might argue that personality takes up the space of ones brain or person, but…not all personable people are overweight. Thus personality does not have weight, and is therefore not matter.
Matter ContinuedHow about thought? Again we might argue that thought takes up the space of ones brain and your mother told you about heavy thoughts, but….
Matter ContinuedHow about thought? Again we might argue that thought takes up the space of ones brain and your mother told you about heavy thoughts, but….If you get on the bathroom scale and start having heavy thoughts, your weight does not go up!
Matter ContinuedHow about thought? Again we might argue that thought takes up the space of ones brain and your mother told you about heavy thoughts, but….If you get on the bathroom scale and start having heavy thoughts, your weight does not go up! That means thought is not matter, so if someone studies thought, they are not doing chemistry.
Examples of Chemistry• The study of why wood burns
• The study of why cement does not burn
• The study of why nails rust
• The study of milk spoiling
These all fit the definition of chemistry since they deal with change and matter
History of Chemistry
Who were the first chemists?
History of ChemistryWho were the first chemists?
History of ChemistryWho were the first chemists?
Cavemen
History of ChemistryWhat kind of matter and changes did the cavemen study?
History of ChemistryWhat kind of matter and changes did the cavemen study? Fire and food!
Archeologists have found evidence of fire in caves and animal bones too. Cooking meat makes meat chewable. Chewing raw meet wears out ones jaw.
History of ChemistryThe next group that left archeological evidence of chemistry were the Egyptians. Their chemistry involved mummies, textile dyes, ink, paper and paints most of which can be found inside the pyramids.
History of ChemistryThe first group of people to leave written records of their chemistry were the Greeks. From Greek writings, we can see that the Greeks made observations, and created reasons for these observations, called hypothesis. They did not attempt to prove their hypothesis by experimentation, thus their chemistry efforts were philosophical in nature as opposed to science in nature.
History of ChemistryThe first group of chemists to test hypothesis with experiments were the alchemists. Alchemists were a group of Europeans that were trying to change matter in to different kinds of matter. For example, they were trying to change lead into gold. The major results of their experiments were to prove most of the Greek ideas of chemistry to be false and to show a clear distinction between science and philosophy.
History of Chemistry
A major short coming of the Alchemists chemistry was irreproducible results, caused by lack of measurement understanding. For example, on day 1 mixing two kinds of matter produced black matter, while doing the same thing the next day produced red matter. The Alchemists were the first group of chemists to make observations, create hypothesis, and to test their hypothesis with experiments.
Modern Chemistry
Antoine Lavoisier was the founder of modern chemistry by making careful measurements.
Modern ChemistryLavoisier’s careful measurements now made experiments reproducible. Chemists in other countries could now do the same experiment and get the same results. This now allowed chemists to prove a hypothesis to be correct by experimentation, thus leading to the discovery of theories and laws.
Modern Chemistry
• Law of Conservation of Mass
• Atomic Theory
Lavoisier’s Theories and Laws
Scientific MethodIs a sequence of thoughts and
experiments containing the following:
• A hypothesis is a tentative and testable explanation for an observation or a series of observations.
• A scientific theory is a general explanation of widely observed phenomena that have been extensively tested.
Classification of Matter
Matter
Homogeneous Heterogeneous
SolutionsSubstances
Elements Compounds
Classification of Matter
Homogeneous matter looks the same everywhere with a microscope, but since we lack microscopes we will use our eyes and not our imagination. Heterogeneous matter does not look the same everywhere.
Homogeneous and Heterogeneous
Classification of MatterHomogeneous or Heterogeneous?
Wood Carpet Margarine Gold
Classification of MatterHomogeneous or Heterogeneous?
Wood Carpet Margarine GoldHeterogeneous
Classification of MatterHomogeneous or Heterogeneous?
Wood Carpet Margarine GoldHeterogeneous Heterogeneous
Classification of MatterHomogeneous or Heterogeneous?
Wood Carpet Margarine GoldHeterogeneous Heterogeneous Homogeneous
Classification of MatterHomogeneous or Heterogeneous?
Wood Carpet Margarine GoldHeterogeneous Heterogeneous Homogeneous Homogeneous
Classification of MatterSolution is a homogeneous random combination of two or more different types of matter.
For example a random amount of salt and water combined together produces a homogeneous mixture, called salt water. Random combination means some salt and some water.
Classification of MatterAny combination the produces a homogeneous result that is not randomly created is called a substance.
For example, combining two hydrogen atoms and one oxygen atom produces a compound of water, which is a substance. Or the combination of two oxygen atoms, gives a molecule of oxygen.
Classification of Matter
Homogeneous matter created by the same atom is called and element. Exact combinations of different elements is called a compound.
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand•Sea water•Tap water•Steel•Antimony•Air•Distilled water•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water•Tap water•Steel•Antimony•Air•Distilled water•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water•Steel•Antimony•Air•Distilled water•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel•Antimony•Air•Distilled water•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony•Air•Distilled water•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air•Distilled water•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water-Compound•Cement•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water-Compound•Cement-Heterogeneous•Wine
Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water-Compound•Cement-Heterogeneous•Wine-Solution
Classification of Matter• Types of Matter
1. Pure Substances have the same physical and chemical properties throughout.
2. Mixtures are composed of two or more substances (elements or compounds) in variable proportions.
Elements and Compounds• Most elements are not found in the world in
the pure form. They are found in compounds.
• Hydrogen is found in water, H2O, and other hydrogen containing compounds.
• The law of constant composition states that every sample of a compound always contains the same elements in the same proportions.
Pure Substances• Two Groups
1. An element is the simplest kind of material with unique physical and chemical properties.
2. A compound is a substance that consists of two or more elements linked together in definite proportions.
An Atomic View• An atom is the smallest particle of an element
that retains the chemical characteristics of that element.
• A molecule is a collection of atoms chemically bonded together having constant proportions.
Chemical Formulas• Chemical bonds link
atoms together to make molecules.
• Chemical formulas use symbols to represent atoms with subscripts to identify the number of each atom present.
Chemical Reactions• Chemical reactions show
the transformation of one or more substance into different substances.
• Chemical equations use chemical formulas to express the identities and quantities of substances involved in a reaction
Separating Mixtures
• No chemical reactions are needed to isolate the constituents in a mixture.
Filtration
Distillation
Filtration
Distillation
Properties of Matter• Intensive property - a characteristic that is
independent of the amount of substance present.Examples: color, hardness, etc.
• Extensive property - a characteristic that varies with the quantity of the substance present.Examples: length, width, mass, etc.
State of Matter• Solids have definite shapes and
volumes.
• Liquids occupy definite volumes, but do not have definite shapes.
• Gases have neither a definite shape nor volume.
• Plasma, not found on earth, but stars, similar to a gas, but a mixture of subatomic particles
Examples
Making Measurements• Accurate measurements are essential
for our ability to characterize the physical and chemical properties of matter.
• Standardization of the units of measurements is essential.
Some Prefixes for SI Units
Prefixes Value
Name Symbol Exponential
Mega M 106
Kilo k 103
Hecto h 102
Deka da 10
Deci d 10-1
Centi c 10-2
Milli m 10-3
Micro 10-6
Nano n 10-9
Pico p 10-12
Memorize the ones in blue
SI Base Units
Quantity Unit NameUnit
Abbreviation
Mass Kilogram kg
Length Meter m
Temperature Kelvin K
Time Second s
Energy Joule J
Electrical Current Ampere A
Amount of Substance
Mole mol
Luminosity Candela cd
English Metric Conversions
• 1 in = 2.54 cm Length
• 1 lb = 453.6 g Mass
• 1qt = 946.4 mL Volume
These are definitions, thus lacking significant figures
Scientific Measurements • A measurement always has some
degree of uncertainty due to the fact that measuring devices have scales. A digit that must be estimated is called uncertain due to the fact that it is between the scale lines, or appears to be on a scale line.
Counting Significant Figures• All numbers counted in a measurement are All numbers counted in a measurement are
significant.significant.• Zero’s sandwiched by two numbers are Zero’s sandwiched by two numbers are
counted.counted.• If a zero is used to locate a decimal, then it If a zero is used to locate a decimal, then it
is not a number, but a spacer and is not is not a number, but a spacer and is not counted.counted.
• Additional information sometimes is Additional information sometimes is available the make zeros both numbers and available the make zeros both numbers and decimal spacers.decimal spacers.
Practice How many significant figures are in the How many significant figures are in the
following numbers?following numbers?
0.04550 g
100 lb
101.05 mL
350.0 g
Practice How many significant figures are in the How many significant figures are in the
following numbers?following numbers?
0.04550 g
100 lb
101.05 mL
350.0 g
Practice How many significant figures are in the How many significant figures are in the
following numbers?following numbers?
0.04550 g 4 significant figures
100 lb
101.05 mL
350.0 g
Practice How many significant figures are in the How many significant figures are in the
following numbers?following numbers?
0.04550 g 4 significant figures
100 lb 1 significant figure
101.05 mL
350.0 g
Practice How many significant figures are in the How many significant figures are in the
following numbers?following numbers?
0.04550 g 4 significant figures
100 lb 1 significant figure
101.05 mL 5 significant figures
350.0 g
Practice How many significant figures are in the How many significant figures are in the
following numbers?following numbers?
0.04550 g 4 significant figures
100 lb 1 significant figure
101.05 mL 5 significant figures
350.0 g 4 significant figures
Practice How many significant figures are in the How many significant figures are in the
following numbers?following numbers?
0.04550 g 4 significant figures
100 lb 1 significant figure
101.05 mL 5 significant figures
350.0 g 4 significant figures
Counting Significant Figures• Exact numbers Exact numbers have an infinite have an infinite
number of significant figures.number of significant figures.• Exact numbers Exact numbers are either counted are either counted
or defined.or defined.
• 1 inch = 2.541 inch = 2.54 cm, exactlycm, exactly
Rounding Rules• Addition and Subtraction: Round Addition and Subtraction: Round
answer so that it contains the same answer so that it contains the same number of number of decimal places decimal places as the as the measurement with the lease measurement with the lease number of number of decimal placesdecimal places..
• 6.8 + 11.934 = 18.734 6.8 + 11.934 = 18.734 18.7 (1 18.7 (1
decimal place)decimal place)
Rounding Rules
• Multiplication and Division: Round Multiplication and Division: Round answer so that it contains the same answer so that it contains the same number of number of significant figures significant figures as the as the measurement with the least number of measurement with the least number of significant figuressignificant figures..
• 6.38 6.38 2.0 = 12.76 2.0 = 12.76 13 (2 sig figs) 13 (2 sig figs)
Precision and Accuracy
Precision is how close measurements are to each otherAccuracy is how close a measurement is to the true value.
There have been many serious incidents that have resulted from
errors in converting between systems of units.
Air Canada Flight 143
(Google it for more details)
Unit Conversion Accidents
$125 million Mars Climate Orbiter.
Lost in Space.
Dp you think there is the potential to make errors in the
conversion of units for health care providers?
Unit Conversion Accidents
Conversion Problem Steps
1. Write down the number and unit.2. Draw lines; a vertical line after the number an
unit and horizontal line below the number and unit.
3. Insert a fractional fact to cancel out the original unit.
4. Compare the new unit to the asked for unita. If the same, you are done.
b. If not the same, repeat step 3.
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
47.2 mg
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
47.2 mg
Step 2. Draw lines
47.2 mg
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
47.2 mg
Step 2. Draw lines
47.2 mg
Step 3. Insert fractional fact crossing out original unit
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
47.2 mg
Step 2. Draw lines
47.2 mg
Step 3. Insert fractional fact crossing out original unit
47.2 mgmg10-3 g
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
47.2 mg
Step 2. Draw lines
47.2 mg
Step 3. Insert fractional fact crossing out original unit
47.2 mgmg10-3 g
Step 4. Compare new unit to the asked for unit.
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
47.2 mg
Step 2. Draw lines
47.2 mg
Step 3. Insert fractional fact crossing out original unit
47.2 mgmg10-3 g
Step 4. Compare new unit to the asked for unit.A. If the same you are doneb. If not the same repeat step 3.
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
47.2 mg
Step 2. Draw lines
47.2 mg
Step 3. Insert fractional fact crossing out original unit
47.2 mgmg10-3 g
Step 4. Compare new unit to the asked for unit.A. If the same you are doneb. If not the same repeat step 3.
= 0.0472 g
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
702 cL
Step 2. Draw lines
702 cL
Step 3. Insert fractional fact crossing out original unit
702 cLcL10-2 L
Step 4. Compare new unit to the asked for unit.A. If the same you are doneb. If not the same repeat step 3.
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
702 cL
Step 2. Draw lines
702 cL
Step 3. Insert fractional fact crossing out original unit
702 cLcL10-2 L
Step 4. Compare new unit to the asked for unit.A. If the same you are doneb. If not the same repeat step 3.
Not a match repeat step #3
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
702 cL
Step 2. Draw lines
702 cL
Step 3. Insert fractional fact crossing out original unit
702 cLcL10-2 L
Step 4. Compare new unit to the asked for unit.A. If the same you are doneb. If not the same repeat step 3.
10-6 L
μL
It’s a match, done
Sample Conversion Problems
1. How many grams are in 47.2 mg? 2. Change 702 cL to µL.
Step 1. Write down the number and unit.
702 cL
Step 2. Draw lines
702 cL
Step 3. Insert fractional fact crossing out original unit
702 cLcL10-2 L
Step 4. Compare new unit to the asked for unit.A. If the same you are doneb. If not the same repeat step 3.
10-6 L
μL
It’s a match, done
= 7.02 x 106 μL
DENSITY• What is heavier 5 pounds of lead or 5
pounds of feathers?
• What takes up more space, 5 pounds of lead or 5 pounds of feathers?
DENSITY
• What is heavier 5 pounds of lead or 5 pounds of feathers? Both the same. This is an old riddle to confuse density with weight
• What takes up more space, 5 pounds of lead or 5 pounds of feathers?
DENSITY
• What is heavier 5 pounds of lead or 5 pounds of feathers? Both the same. This is an old riddle to confuse density with weight
• What takes up more space, 5 pounds of lead or 5 pounds of feathers? Feathers, since they are less dense.
We can determine the volume of irregularly shaped objects by displacement.
How can we determine the volume of a gas?Gases fill whatever container they are placed in. So it’s the volume of the container !
Archimedes Principle
DENSITY UNITS
g/ml, g/cm3, (for solids and liquids), or g/L for gases
MATTER AND ENERGYThe End