let’s get started how to pass chemistry recognize from the start that chemistry is a subject that...

Let’s Get Started

How to Pass Chemistry

•Recognize from the start that chemistry is a subject that requires time and work. Be committed to investing the time and effort that the course demands.

How to Pass Chemistry

•Believe in yourself and your capabilities. Even though chemistry can be difficult for some people, you can understand it if you work at it.

How to Pass Chemistry

•Come to class prepared and take lots of notes. Always bring your notebook, your periodic table, and your calculator.

How to Pass Chemistry

• Don't be embarrassed about asking for help. Everyone needs help sometimes. It's smarter to get help when you need it than to try to do without it. Your teacher would much rather help you than flunk you. Teachers have a lot of respect for students who care enough about the course to get help when they need it.

How to Pass Chemistry• When you come for help, have a specific

problem or list of problems. A teacher can't help you much if you come in with something vague like, "I just don't understand this course" or "this chapter." The teacher will be able to do much more for you if you say, "I tried to work problem 3.2 and I keep getting an answer of 4.6 but my book says that it's 194. Where am I going wrong?" Or "the book says I have to take the square root of this but I don't understand why." Be as specific as you can!

HELP!!!!!!• I am available for chemistry help 5th period,

every day of the cycle except day 1.

• I am here every day at 6am, and most afternoons until 4pm.

• There are help periods throughout the day with various chem teachers.

• Bottom line: HELP IS ALWAYS AVAILABLE!

What is Chemistry?• The study of the composition of

matter and the changes that matter undergoes.

• Since everything is made of matter, chemistry affects all aspects of life.

Areas of Study• Organic chemistry-substances that contain

carbon

• Inorganic chemistry-substances that do not contain carbon

• Biochemistry-life processes, cellular processes

• Analytical chemistry-focuses on the composition of matter

• Physical chemistry-study of changes in matter

Why Study Chemistry at All?

500 billion dollars a year in sales

5.8 million jobs (4% total U.S. work force)

$68,000 average salary

96% of all goods touched by chemistry

Why Study Chemistry at All?

• Why does ice float on water?

• Why do we put salt on roads in the winter?

• Where do the colors from fireworks come from?

• How do air bags work?

• How does UnderArmor work?

• What makes graphite so versatile for products?

• Why are steroids so hard to detect?

• How is bulletproof glass bulletproof?

Scientific Method

• A way to gather knowledge and answer questions.

• Observation > • Question > • Hypothesis > • Experiment >• Conclusion (or return to Question)

Units of Measurement• We will use the metric system (SI Units)

• Mass and Weight are not the same.

• Measurement Unit Symbol

• Mass kilogram kg

• Length meter m

• Time second s

• Count mole mol

• Temp. Centigrade C°

KelvinK

Prefix Symbol What it does to the Base Unit

Mega M x 1,000,000

Kilo k x 1000

Deca D x 10

Deci d x 0.1

Centi c x 0.01

Milli m x 0.001

Nano n x 0.000000001

Pico p x 0.000000000001

Prefix SymbolWhat it does to the

Base Unit

Mega M x 1,000,000

Kilo k x 1000

Deca D x 10

Deci d x 0.1

Centi c x 0.01

Milli m x 0.001

Micro µ x 0.000001

Nano n x 0.000000001

Pico p x 0.000000000001

Energy• The capacity to do work or produce heat

–Kinetic

–Potential

–Radiant

• Law of Conservation of Energy-in any process, energy is neither created nor destroyed. It can be transformed from one type to another, but it is conserved.

Matter• Anything that has mass and volume.

–Solid-high density, holds its own shape

–Liquid-high density, adopts shape of its container

–Gas-low density, expands to fill its container

–Plasma-low density, EXTREMELY high temp.

Law of Conservation of Matter

• In any process, matter is neither created nor destroyed.

• This is true in everything but nuclear decay and nuclear explosions.

Properties of Substances

• Physical Properties- characteristics of a substance that you can observe without altering the identity of the substance

• Chemical Properties-characteristics of a substance that you can not observe without changing the identity of a substance

Changes to Substances

• Physical Changes- do not alter the identity of the substance

• Examples????

• Chemical Changes-alters the identity of the substance

• Examples????

Matter

Pure Substances Mixtures

Element

• The simplest form of matter with a unique set of properties.

• Only one kind of atoms.

• Examples:

Compound

• Two or more elements chemically combined in a fixed proportion.

• Examples:

Mixtures• Physical blend of two or more

substances.

• Examples (all 3 phases):

• Heterogeneous-not uniform; the ingredients can be seen

• Homogeneous-uniform; the ingredients can not be seen(solutions)

Mixtures

• Heterogeneous-separated by physical means (filtration, decanting, centrifuge)

• Homogeneous-separated by chemical means (distillation, chromatography)

Matter

Pure Substances Mixtures

Elements Compounds Homogeneous Mixtures Heterogeneous Mixtures

For Homework….

• In the textbook,

• P. 47 #’s 12, 14, 16, 17

• P. 52 #’s 20, 21, 24

• P. 55 #’s 28,29,30,32,34

Percent Error• Expresses in a number how close to the actual

value your results are.

• For instance, you were supposed to produce 10g of product in your reaction, but you only produced 9g. Your percent error was 10%.

• %Error = |(Exp. Value) – (Actual value)| x 100%• (Actual value)