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.

COCO2

Properties of a compound are different than properties of the elements that make it up.

Compounds do not look like or act like the elements that form them. WaterH2O Sucrose C12H22O11 Carbon 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 water 6 atoms of hydrogen 3 atoms of oxygen Coefficient X subscript total number of atoms

Coefficient X subscript total number of atoms CO2 One molecule of carbon dioxide 1 atom of carbon 2 atoms of oxygen

Coefficient X subscript total number of atoms 8CO 8 molecules of carbon monoxide 8 atoms of carbon 8 atoms of oxygen

H2O2 Coefficient X subscript total number of atoms 1 molecule of hydrogen peroxide 2 atoms of hydrogen 2 atoms of oxygen \

6C6H12O6 Coefficient X subscript = total number of atoms 6 molecules of sugar 36 atoms of carbon 72 atoms of hydrogen 36 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 Examples NaCl (salt) made of 1 Sodium atom and 1 Chlorine atom ratio of elements=1:1 CO2 (carbon dioxide) made of 1 Carbon atom and 2 Oxygen atoms ratio 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 = 2:2 CO (carbon monoxide) Ratio of elements = 1:1 Assignment: Compound Practice Due Friday

Women in Science Day? Do illiterate people get the full effect of Alphabet Soup?

In chemistry, metal-nonmetal compounds 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 monoxide CO2 = Carbon dioxide SO3 = Sulfur trioxide CCl4 = Carbon tetrachloride

ACIDS HCl - hydrochloric acid (stomach acid) H2SO4 - sulfuric acid (battery acid) HNO3 - nitric acid HC2H3O2 - acetic acid (vinegar) H2CO3 - carbonic acid (in carbonated drinks) BASES NaOH - sodium hydroxide (lye) NH4OH - ammonium hydroxide Ca(OH)2 - calcium hydroxide Mg(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

C2H5OH SiO2 CaO Fe2O3 H2CO3 NaNO3 PbI2 NaOH CaCO3NH3Mg(OH)2 HC2H3O2 N2O ZnCl2 MnO2 CuSO4 Ca(OH)2 NaHCO3 NH4OH H2SO4 C6H12O6 H2O2 NaOH HCl

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

BaCl2Barium Chloride HNO3Nitric Acid C12 H22 O11Sucrose Fe2O3Iron Oxide NH3Ammonia Gas CaOCalcium Oxide H2O2Hydrogen 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

O bjective: 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 Molecule H2O Two atoms of hydrogen One 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 + water C22H O2 ---> 22 CO 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 bicarbonate HC2H3O2 + NaHCO3---> NaC2H3O2 + CO2 + H2O