Chemistry Chapter 2

• What is matter?

• What are atoms?

• How can we tell what they are doing?

• How do we classify them?

Vocabulary 2.1

• Matter scale mixture

• Physical property chemical property

• Element period group

• Substance chemical change

• Physical change macroscopic

• Microscopic mole atomic number

Vocabulary 2.2

• Molecule chemical formula

• Ions ionic bond compound

• Structural diagram space filling model

• Formula mass

Vocabulary 2.3

• Heterogeneous homogeneous

• Solute concentration solubility

• Dissolved molar volume solvent

• Solution concentrated

• Dilute insoluble molarity

• Partial pressure

Matter and Atoms

• Matter: any substance which has mass and occupies space.

• Matter is nothing more than "stuff". It is protons, neutrons, electrons, and whatever else fundamentally causes "stuff" to exist.Mass is the amount of matter in a body.

Matter and elements

• A pure substance cannot be separated into a simpler substance by physical means

• An element cannot be separated into a simpler substance by chemical or physical means.

Mixtures

• Mixtures are matter that contains more than one substance (a tree, orange juice, chicken noodle soup)

• Most ordinary matter is mixtures– Mixtures can be separated into their

components by physical means.

Physical properties

• Physical properties are properties that you can measure or see through observation

• Include size, color, texture, brittleness, malleability, phase (solid, liquid, gas) freezing point, boiling point, etc

Physical change

• A change that still leaves the same chemical substance. Melting, boiling, dissolving, evaporating are some physical changes.

Chemical properties

• Those qualities which identify how a specific type of matter will react and change when combined with another type of matter.

• Things such as reactivity, oxidation states, flammability, and corrosiveness

Chemical Changes

• A chemical change transforms a chemical into a different substance

• Chemical changes are caused by chemical reactions.

• A chemical change or chemical reaction changes what the substance is

Macroscopic scale

• When things are large enough for use see or directly measure, such as mass and temperature

• Microscopic When we have to understand things at the atomic level (not through a microscope0

Elements

• An element cannot be broken down into any simpler chemical substances

• An atom is the smallest part of an element

Periodic table

• A orderly arrangement of the elements. It is organized by their chemical properties.

• Chemical properties are caused by the atom structure of the elements.

Avogadro’s number

• One Avogadro’s number, 6.02 x 1023 of atoms, will equal the atomic mass number in grams.

• One Avogadro’s number of copper atoms is 63.546 grams

• This is one MOLE of copper!!!!!!

Amu and the mole

• One more time

• One Avogadro’s number of an atom or compound is a MOLE. It will weigh the AMU in GRAMS of the element or compound.

Molecules and Compounds

• Most matter exists in molecules and compounds

• A Molecule is a group of atoms chemically bonded together. They can be all the same kind or different kinds of atoms

• A compound is a molecule with different kinds of atoms.

Possibilities

• With the elements (about 92) and the different ways they can combine, there are trillions of possibilities (WOW!)

Chemical formulas

• Compounds are represented by chemical formulas

• H2O =2 hydrogen and 1 oxygen

• Baking soda = NaHCO3

• Means 1 sodium, 1 hydrogen, 1 carbon, and 3 oxygen

Molecules

• The characteristics of a molecule are due to the features of that unique molecule.

• Other molecules with the same chemical formula can be very different because the molecule is different!!!

• See page 50

What do molecules really look like?

• H2SO4

Ionic Compounds

• Ionic compounds have ions, which have an electrical charge, + or –

• The charges hold the molecule together like the poles of a magnet.

• Salt is a common ionic compound

• P 52

The Formula Mass

• The formula mass: An avogadro’s number of a molecule weighs the sum of the atomic mass units in grams

• Water H2O• H = 1 amu• 0 = 16 amu• Water =(2 x1) + 16 = 18 grams for formula

mass• 1 mole water = 18 grams

Chemistry 9.22

• Get books

• Issue

• Cover

• Maintain

• Math

• Collect any missing work from yesterday

9.27

•   “Do the one thing you think you cannot do. Fail at it. Try again. Do better the second time. The only people who never tumble are those who never mount the high wire. This is your moment. Own it.”

• Oprah Winfrey

Tutoring

• Tues-Thursday this week

• Get out quiz from Friday

• Swap, grade

Atoms

• Atoms have protons and neutrons in the nucleus and electrons outside

• An ion has either lost or gained an electron so it has an electric charge

• It is then attracted to ions with an opposite charge

Mixtures and Solutions

Homogenous

• A mixture that contains

• more than one type of matter

• and is the same throughout.

Heterogenous

• A mixture that contains

• more than one type of matter

• and is not the same

• throughout.

Solution

• a mixture that is homogenous on the molecular level. That means there are

no clumps bigger than a molecule.

Solute and Solvent

• A Solute is in a solvent

• Tea in water

Concentration

• How much is in the solution

• A dilute solution has a little solute in the solvent (weak)

• A concentrated solution has a lot of solute in the solvent

Concentration grams/liter

How many grams in how much solvent? Easy!!

Percent solutions is by Mass

If Mr. Barnard weighs 120 kilos and the whole class weighs 2400 kilos then he is 120/2400 X 100 = 5% of class by mass

Molarity

• Moles per liter of solution

• 3 moles in 2 liters is 3/2 = 1.5 Moles per liter = a 1.5M solution

• Molarity = moles solute ÷ volume of solution

Gas

• 1 mole of gas = 22.4 liters of volume at STP

• STP = Standard temperature and pressure

• Pressure = 1 atmosphere

• Temp = 0 degrees C

Partial Pressures

• The pressure is the sum of the pressures of all the gasses (p63)

9.28

• “Multi-tasking - Screwing everything up simultaneously.”

Math

• Video clip math

• Set up labs for next few days

• Math quiz

9/29

• “I'm presently incarcerated. Convicted of a crime I didn't even commit. Hah! "Attempted murder"? Now honestly, what is that? Do they give a Nobel prize for attempted chemistry? Do they?”

•  Matt Groening

• (Creator of the Simpsons)

Today

• Grams and moles and molecules, oh my!

• % solution (Hey! An easy one baby!!)

September 30

• “There is no such thing as a failed experiment, only experiments with unexpected outcomes”

– Buckminster Fuller

Today

• Quiz

• Survey

• Set up labs/prepare areas

• Have you started reviewing for your test?

October 1, 2010

• “I know the world isn't fair, but why isn't it ever unfair in my favor?”

• Bill Watterson

Try the labs

• Study over weekend

• Not much 2.3, will keep coming back to this chapter

• Groups