Catalyst – October 2(6)-1, 2010 Monday Mystery Element 1. Used in space shuttle parts 2. One of its compounds looks like a diamond 3. Its name probably originated from the Arabic word “zargun” Sit where you like, but make sure you can stay focused and see the board!

Catalyst – October 2(6)-1, 2010 Monday Mystery Element 1. Used in space shuttle parts 2. One of its compounds looks like a diamond 3. Its name probably originated from the Arabic word “zargun” ZIRCONIUM!

Today’s Agenda  Catalyst  Chemistry Prom Begins!  Intro to Unit 4 – Chemical Reactions!  Practice Time!  Exit Question

Today’s Objectives  SWBAT interpret chemical equations.  SWBAT write skeleton (formula) equations from word equations.

What is a CHEMICAL REACTION???

What to Expect at Chemistry Prom  Learn how to interpret and write chemical reactions  Learn about 5 types of chemical reactions  Show off your chemical dance moves  Crown a Chemistry Prom King and Queen from each class  Remember Chemistry Prom with a Project

Chemistry Prom King and Queen Eligibility Requirements  Complete all homework on time  Stay focused in class  Complete all classwork  No sleeping  Miss no more than one day of school this week

The Element Song! 

Do you know what a chemical reaction is???? Key Point #1: A chemical reaction is a process involving one or more substances changing into NEW SUBSTANCES.

DANCE FLOOR TIME! Chemical Reaction: YES or NO? 1. Milk going sour 2. Cutting a piece of paper 3. Eggs rotting 4. Baking soda and vinegar mixing to produce carbon dioxide 5. Crushing an aluminum can before recycling it 6. Recycling an aluminum can 7. Mg + O 2  MgO

Chemical Equations! Key Point #2: We use CHEMICAL EQUATIONS to show what happens in chemical reactions. C 3 H O 2  3 CO H 2 0

Chemical Equations  Chemical equations are similar to algebraic equations in that the total number of atoms of each element must be equal on each side A mathematical equation: x + 2x = 3x A chemical equation: C 3 H O 2  3 CO H 2 0

Parts of a Chemical Equation Key Point #3: A chemical equation identifies the starting chemicals as REACTANTS and the finishing chemicals as PRODUCTS. Reactants  Products Example (combustion of propane) C 3 H O 2  3 CO H 2 0

3 Types of Chemical Equations There are 3 ways to write chemical equations: 1. Word Equations 2. Skeleton Equations 3. Balanced Equations

Phase Notations There are 4 phase notations used in equations: 1. Solid (s) 2. Liquid (l) 3. Gas (g) 4. In water/Aqueous (aq)

Parts of Chemical Equations Reactants  Products C 3 H O 2  3 CO H 2 0 When you see “yields” or “produces” or “forms,” use an arrow (  ) When you see “reacts with” or “and,” use a plus sign (+)

Word Equations Key Point #4: Word equations use WORDS to show chemical reactions. Solid iron and chlorine gas react to form solid iron(III) chloride  It’s like a short “chemical sentence” describing a chemical reaction!

Skeleton Equations Key Point #5: Skeleton equations use CHEMICAL FORMULAS rather than words to identify products and reactants.

Word  Skeleton Examples 1. Write the skeleton equation from the following word equation: Solid iron and chlorine gas react to form solid iron(III) chloride. Just replace all names with formulas! Don’t forget phase notations!

Write the skeleton equation… Solid iron and chlorine gas react to form solid iron(III) chloride.  Metals: Just write the element symbol  Diatomics: Molecules with 2 atoms of the same element  Start at 7, make a 7, don’t forget the “H!” Skeleton Equation: Fe (s) + Cl 2 (g)  FeCl 3 (s)

Skeleton Equations – Examples  Write skeleton equations for the following word equations: 1. Solid magnesium and chlorine gas react to form solid magnesium chloride. 2. The reaction of hydrogen gas and bromine gas yields hydrogen bromide gas. 3. Aqueous sodium hydroxide reacts with aqueous hydrogen chloride to produce aqueous sodium chloride and liquid dihydrogen monoxide.

Skeleton Equations – Your Turn!  Write the skeleton equations for the following word equations: 1. Hydrogen gas reacts with iodine gas to yield gaseous hydrogen iodide. 2. Gaseous carbon monoxide reacts with oxygen gas to produce carbon dioxide gas. 3. Solid potassium chlorate (chlorate = ClO 3 1- ) yields solid potassium chloride and oxygen gas. TURN IN CLASSWORK TO FOLDER

Exit Question HW: BOTH SIDES OF WORKSHEET 1. What is written on the LEFT side of the arrow in a chemical equation: PRODUCTS or REACTANTS? 2. Which of the following is a correctly written SKELETON EQUATION for reaction between solid lithium and oxygen gas? A) Li + O  LiO B) Li + O 2  Li 2 O C) Li (s) + O 2 (g)  Li 2 O (s) D) LiO  Li + O