COMPOUNDS

WHAT IS A COMPOUND?

A pure substance made of 2 or more elements that are chemically combined, forming a molecule.

If the proportion of elements is changed in a molecule, the compound changes.

 Water  Hydrogen Peroxide.

CO CO2

Properties of a compoundare different thanproperties of the elements that make it up.

Compounds do not look like or act like the elements that form them.

Water H2OSucrose  C12H22O11Carbon dioxide  CO2 Sodium chloride  NaCl Baking soda  NaHCO3 

3H2O

3 Molecules of water

6Atoms of Hydrogen

3 Atoms of Oxygen

3H2O

The 3 is the COEFFICIENT

The 2 is the SUBSCRIPT

3H2O

The COEFFICIECT tells how many molecules

The SUBSCRIPT tells how many atoms.

 Coefficient  X subscript total number of atoms

3H2O

Three molecules of water6 atoms of hydrogen3 atoms of oxygen

 Coefficient  X subscript total number of atoms

 Coefficient  X subscript total number of atoms

CO2

One molecule of carbon dioxide1 atom of carbon2 atoms of oxygen

 Coefficient  X subscript total number of atoms

8CO

8 molecules of carbon monoxide8 atoms of carbon8 atoms of oxygen

H2O2

 Coefficient  X subscript total number of atoms

1 molecule of hydrogen peroxide2 atoms of hydrogen2 atoms of oxygen

\

6C6H12O6

Coefficient X subscript = total number of atoms

6 molecules of sugar36 atoms of carbon72 atoms of hydrogen36 atoms of oxygen

144 total atoms

Writing CHEMICAL FORMULAS

A group of element symbols that shows 2 things:the make-up of elements the ratio of the elements in a compound

ExamplesNaCl (salt)made of 1 Sodium atom and 1 Chlorine atomratio of elements=1:1

CO2 (carbon dioxide)made of 1 Carbon atom and 2 Oxygen atomsratio of elements = 1:2

More examples:

H2O (water) ratio of elements = 2:1

Ca(OH)2 (calcium hydroxide)ratio of elements= 1:2:2

H2O2 (hydrogen peroxide)

ratio of elements = 2:2CO (carbon monoxide)

Ratio of elements = 1:1

Assignment: Compound PracticeDue Friday

Women in Science Day?

Do illiterate people get the full effect of Alphabet Soup?

In chemistry, metal-nonmetalcompounds are called SALTS.

2 RULES FOR NAMING COMPOUNDS

Rule #1: METAL-NONMETAL COMPOUNDS

Use “ide” ending

Metal is always written first

EXAMPLES:

ZnCl2 Zinc chloride

NiI2 Nickel iodide

Fe2O3 Iron oxide (rust)

MgS Magnesium sulfide

Rule #2: NONMETAL COMPOUNDS

- use prefixes -

“Mono” = 1“Di” = 2“Tri” = 3“Tetra” = 4

EXAMPLES:

CO = Carbon monoxideCO2 = Carbon dioxideSO3 = Sulfur trioxideCCl4 = Carbon tetrachloride

ACIDS

HCl - hydrochloric acid (stomach acid)H2SO4 - sulfuric acid (battery acid)HNO3 - nitric acidHC2H3O2 - acetic acid (vinegar)H2CO3 - carbonic acid (in carbonated drinks)

BASES

NaOH - sodium hydroxide (lye)NH4OH - ammonium hydroxideCa(OH)2 - calcium hydroxideMg(OH)2 - magnesium hydroxide (Rolaids, Milk of Magnesia)

Some Common Compounds

OTHERS (SOME WE USE IN LABS)

C6H12O6 - glucose

MnO2 - manganese dioxide

CO - carbon monoxide

SO2 - sulfur dioxide

CuSO4 - copper sulfate

PbI2 - lead iodide

KI - potassium iodide

Fe2O3 - iron oxide (rust)

BaCl2 - barium chloride

NaNO3 - sodium nitrate

ZnCl2 - zinc chloride

N2O - nitrous oxide (laughing gas)

Let's start with using your flash cards..............

C2H5OHSiO2CaO Fe2O3H2CO3NaNO3

PbI2NaOHCaCO3NH3 Mg(OH)2 HC2H3O2

N2OZnCl2MnO2 CuSO4 Ca(OH)2

NaHCO3

NH4OHH2SO4C6H12O6H2O2NaOHHCl

Dot Diagrams Practice

Beryllium

Silicon

Chlorine

Neon

Argon

Magnesium

Sulfur

Calcium

Lewis Dot Diagrams of the First Three Periods

Lithium

Sodium

Potassium

Let's start with using your flash cards..............

Write the compound in your notebook, write the name of the compound next to it. See how many you know!

BaCl2

HNO3

C12 H22 O11

Fe2O3

NH3

CaO

H2O2

C6H12O6

CuSO4

C2H5OH

SiO2

Ca(OH)2

HCl

Mg(OH)2

BaCl2 Barium Chloride

HNO3 Nitric Acid

C12 H22 O11 Sucrose

Fe2O3 Iron Oxide

NH3 Ammonia Gas

CaO Calcium Oxide

H2O2 Hydrogen peroxide

C6H12O6 Glucose

CuSO4 Copper Sulfate

C2H5OH Ethanol

SiO2 Silicon dioxide

Ca(OH)2 Calcium Hydroxide

HCl Hydrochloric acid

Mg(OH)2 Magnesium hydroxide

Molecules

A molecule contains two or more atoms bonded together into one particle.

 Oxygen atom  Oxygen molecule (O2 )

  Hydrogen atom   Water molecule (H2O)

    Does one atom make a difference in a molecule?  

CO  CO2

Objective: The smallest part of a compound that still has the properties of that compound is called a molecule. Molecules are groups of atoms that are chemically bonded together due to the interactions of their electrons. Today, we are going to construct some basic molecules to strengthen our understanding of why certain atoms prefer to bond with each other.

Procedure: Our task today is to construct 15 molecule models. Then, we are going to draw, label and color these models on the back of this sheet. Use the information in the table below when creating your models so that we have consistency throughout the classroom. Provide a key for your drawings.

ELEMENT

COLOR No. of BONDS

Hydrogen

Yellow 1

Sodium Purple 1

Chlorine Green 1

Oxygen Red 2

Nitrogen Blue 3

Carbon Black 4

CH4

2 CH4

C2H6

H2 

4 H2

H2O

2H2O

NaCl

2HCl

NaOH

2 H2O2

NH3

CCl2H2

NaNH2

N2 + 2 H2 + 2 O2

Water MoleculeH2O

Two atoms of hydrogenOne atom of oxygen

Fire needs oxygen so in this demo, you can see the candle burning normally in air in the presence of oxygen.

The combustion reaction is:wax + oxygen in the air ---> carbon dioxide + waterC22H44 + 33 O2 ---> 22 CO2 + 22 H2O + heat energy

When the baking soda and vinegar combine, they form carbon dioxide gas. Carbon dioxide is more dense than air, so therefore it fills the bottom of the beaker first.

The carbon dioxide slowly rises to the top of the beaker, forcing the air with oxygen out of the beaker. Since there is a lack of oxygen, the flame is extinguished.

vinegar + baking soda ---> sodium acetate + carbon dioxide gas +water acetic acid + sodium bicarbonateHC2H3O2 + NaHCO3---> NaC2H3O2 + CO2 + H2O