Unit 3 - Chemistry

Covalent Compounds A compound composed of only non-metals Ex. CO 2, C 12 H 22 O 11 Naming Rules: 1. List the central atom first, the other atom second. 2. For the first atom, if more than one atom present use a prefix to indicate how many atoms are present. (don’t need prefix mono-) 3. For the second atom, use a prefix to determine how many atoms are present. (Need prefix mono-) Change the ending to –ide. Ex. CO 2 Carbon Dioxide

Prefixes Mono- = 1 Di- = 2 Tri- = 3 Tetra- = 4 Penta- = 5 Hexa- = 6 Hepta- = 7 Octa- = 8 Nona- = 9 Deca- = 10

Assignment Name the following Compounds using the previous naming rules (not common names) 1. H 2 O 2. NH 3 3. PCl 5 Write the Formula for the following Compounds 1. Dinitrogen tetraoxide 2. Diphosphorous pentaoxide 3. Xenon Hexafluoride

The Chemical Equation Word Equation: describes a chemical process in terms of its reactants and products Ex. Gasoline and oxygen combine to form carbon dioxide and water. Gasoline + Oxygen  carbon dioxide + Water Reactants are on the left-hand side (what you start with) Products are on the right-hand (what you end up with) separated by an arrow pointing to Products Different parts on either side of the equation are separated by a plus sign

Assignment Create Word Equations for the following: 1. Hydrogen and Oxygen combine to form Water. 2. Hydrogen Peroxide breaks down into Oxygen and Water. 3. Carbonic acid breaks down into water and carbon dioxide.

Types of Reactions Combination Reaction: When two or more elements and/or compounds combine to form a single compound nitrogen + hydrogen  ammonia General Form: A + B  AB Decomposition Reaction When a single compound breaks down into two or more elements and/or compounds Hydrogen peroxide  water + oxygen General Form: AB  A + B

Single Replacement A single element replaces an element within a compound Silver Nitrate + Copper  Copper (II) Nitrate + Silver General Form: AC + B  BC + A (  B replaced the A) Double Replacement Two compounds ‘trade’ elements Silver Nitrate + Lead (II) Chloride  Silver Chloride + Lead (II) Nitrate General Form: AC + BD  BC + AD

Combustion The reaction of an element or compound with oxygen Two Types: Metal Oxides Magnesium + Oxygen  Magnesium Oxide General Form: X + O 2  XO (X= any metal; O = oxygen) Hydrocarbons (Complete Combustion) Butane + Oxygen  Carbon Dioxide + Water Hydrocarbon + O 2  Carbon Dioxide + Water

Assignment Go back to our last assignment; beside each word equation, classify the type of reaction

Exothermic or Endothermic? Exo- = outside Endo- = inside -thermic = heat Exothermic – a reaction that releases heat into the environment Ex. Endothermic – a reaction that absorbs heat from the environment Ex.

Lab Experiment We will be investigating reactions and qualifying them as either exothermic or endothermic Problem: What is the relationship between heat and chemical reactions? Materials: Baking Soda Lemon Juice Thermometer CaCl 2 Water (2) 250mL beakers (2) Stir Rods Procedure Data Table Analysis Conclusion

Conclusion of Unit Closed-Book Chemistry Exam Based on previous open-book exam and will include content since