 Take out your Homework.  Identify the reactants and products in the following chemical reaction equations: › 2 Mg (s) + O 2 (g)  2 MgO (s) › CH 4 (g) + 2 O 2 (g)  CO 2 (g) + 2 H 2 O (l)  Write the chemical reaction equation for the following description: › Hydrogen gas and oxygen gas combine to form liquid water.

 Take out your Homework.  Identify the reactants and products in the following chemical reaction equations: › 2 Mg (s) + O 2 (g)  2 MgO (s) › CH 4 (g) + 2 O 2 (g)  CO 2 (g) + 2 H 2 O (l) › Reactants are on the left and products on the right of the arrow.  Write the chemical reaction equation for the following description: › Hydrogen gas and oxygen gas combine to form liquid water. › 2 H 2 (g) + O 2 (g)  2 H 2 O (l)

 I can compare and contrast different types of chemical reactions.  I can define and identify a balanced chemical equation.  I can balance simple chemical equations.

 Catalyst (10)  Balancing Notes & HW Review (20)  Group Work: Balancing Chemical Equations. (40)  Types of Chemical Equations Reading Activity (40) › Group Work (20) › Presentations & Debrief (20)  Exit Slip (10)

 Matter cannot be created or destroyed in a chemical reaction  The number of atoms on the reactant side must equal the atoms of the products+ H2H2H2H2 H2OH2OH2OH2O O2O2O2O2 (g) (l) HH OO HH O Unbalanced! HH O HH Balanced!

 A chemical equation is “balanced” when there are the same number of atoms of each element on both sides of the arrow. NaHCO 3 (s) + HC 2 H 3 O 2 (aq)  NaC 2 H 3 O 2 (aq) + CO 2 (g) + H 2 O (l) Is it balanced?

 Determine the number of atoms of each element in the reactants and products. Then, state whether the equation is balanced. 1. P 4 + O 2 → P 2 O 5 2. C 3 H 8 + O 2 → CO 2 + H 2 O 3. Ca 2 Si + Cl 2 → CaCl 2 + SiCl 4 4. Si + CO 2 → SiC + SiO 2 Not balanced.

 Only the coefficients can be changed! H2H2H2H2 H2OH2OH2OH2O+ O2O2O2O2 (g) (l) H = O = H = O = coefficient

 Always balance non-Oxygen’s & Hydrogen’s first (ex. Chlorine)  Then balance Hydrogens  Balance Oxygens Last

1. P 4 + O 2 → P 2 O 5 P O 2 → 2 P 2 O 5 2. C 3 H 8 + O 2 → CO 2 + H 2 O C 3 H O 2 → 3 CO H 2 O 3. Ca 2 Si + Cl 2 → CaCl 2 + SiCl 4 Ca 2 Si + 4 Cl 2 → 2 CaCl 2 + SiCl 4 4. Si + CO 2 → SiC + SiO 2 2 Si + CO 2 → SiC + SiO 2

 Instructions: › Work with the person next to you. › You have two worksheets to work on.  1. “Is it balanced?” Determine whether the chemical equation is balanced by counting atoms in the reactants and products.  2. “Balancing Act” Practice balancing equations. › What you do not finish is homework. › Ms. Boon will stamp your work when you are done. › Once you have a stamp, you may check your answers on the posted answer sheet.

 Atoms are not created or destroyed during a chemical reaction.  Scientists know that there must be the same number of atoms on each side of the equation.  To balance the chemical equation, you must add coefficients to the different parts of the equation.

 You will work in groups of four or five at your table.  Fold a sheet of paper into four squares.  Label each square: 1.Synthesis reaction 2.Decomposition reaction 3.Single Replacement Reaction 4.Double Replacement Reaction  You will be assigned one reaction.  Read the section on that reaction, define it, give an example, and draw a picture in your chart. (7 min)  Take turns sharing with your group. (8 min)  Take notes on the other 3 reactions.  If you finish early, read the entire article.

 Two substances combine to make one  Synthesis  Synthesis means “to make”+ H2H2H2H2 H2OH2OH2OH2O O2O2O2O2 (g) (l) HH OO HH HH O H H O

SYNTHESIS Na + Cl 2  NaCl

 One substance breaks down into 2  Decomposition  Decomposition means “to break down” or “decay” H H N+ NH 3  H2H2H2H2 (g) (l) N2N2N2N2 (g) H H H N H

Decomposition NaCl  Na + Cl 2

3. SINGLE REPLACEMENT AB + C  AC + B

Single Replacement NaBr + Cl 2  NaCl + Br 2

Both elements in two compounds switch places AB + CD  AD + CB

Double Replacement NaBr + Pb 2 S 3  Na 2 S + PbBr 3 K 2 SO 4 + Ba(OH) 2  KOH + BaSO 4

 A hydrocarbon reacts with oxygen gas to produce carbon dioxide and water vapor  Combustion  Combustion means to “burn in oxygen”+ CH 4  H2OH2OH2OH2O O2O2O2O2 CO C2H4C2H4C2H4C2H4 H2OH2OH2OH2O O2O2O2O2 + + C 6 H 12 O 6  H2OH2OH2OH2O O2O2O2O2 CO 2 +

1. Mg + O 2  MgO 2. C 3 H 8 + O 2  CO 2 + H 2 O 3. Na + Cl 2  NaCl 4. C 6 H 6  C + H 2 5. FeO + CO 2  FeCO 3

 Read pp  Do problems pp. 271 #1-3, pp. 298 #1, 2, 3, 5, 6, 7