1 / 27

Balancing Chemical Equations and Types of Chemical Reactions

Balancing Chemical Equations and Types of Chemical Reactions. 09.24 & 09.25 2012 Boon Chemistry. Catalyst. Take out your Homework. Identify the reactants and products in the following chemical reaction equations: 2 Mg (s) + O 2 (g)  2 MgO (s)

inge
Download Presentation

Balancing Chemical Equations and Types of Chemical Reactions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Balancing Chemical Equations and Types of Chemical Reactions 09.24 & 09.25 2012 Boon Chemistry

  2. Catalyst • Take out your Homework. • Identify the reactants and products in the following chemical reaction equations: • 2 Mg (s) + O2 (g) 2 MgO (s) • CH4 (g) + 2 O2 (g)  CO2 (g) + 2 H2O (l) • Write the chemical reaction equation for the following description: • Hydrogen gas and oxygen gas combine to form liquid water.

  3. Catalyst Answers: • Take out your Homework. • Identify the reactants and products in the following chemical reaction equations: • 2 Mg (s) + O2 (g) 2 MgO (s) • CH4 (g) + 2 O2 (g)  CO2 (g) + 2 H2O (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 H2(g) + O2 (g) 2 H2O (l)

  4. Objectives • 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.

  5. Agenda • 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)

  6. Why do we balance Chemical Reactions?

  7. + H2 O2  H2O (g) (g) (l) O O O H H H H H H O H H Law of Conservation of Mass • 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 Unbalanced! Balanced!

  8. Balanced Chemical Equations • A chemical equation is “balanced” when there are the same number of atoms of each element on both sides of the arrow. NaHCO3 (s) + HC2H3O2 (aq) èNaC2H3O2 (aq) + CO2 (g) + H2O (l) Is it balanced?

  9. Is it balanced? Practice • Determine the number of atoms of each element in the reactants and products. Then, state whether the equation is balanced. • P4 + O2 → P2O5 • C3H8 + O2 → CO2 + H2O • Ca2Si + Cl2 → CaCl2 + SiCl4 • Si + CO2 → SiC + SiO2 Not balanced. Not balanced. Not balanced. Not balanced.

  10. coefficient + H2 O2  H2O (g) (g) (l) Balancing Equations 2 2 • Only the coefficients can be changed! H = O = 2 4 H = O = 2 4 2 1 2

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

  12. Balancing Practice! • P4 + O2 → P2O5 P4 + 5 O2 → 2 P2O5 • C3H8 + O2 → CO2 + H2O C3H8 + 5 O2 → 3 CO2 + 4 H2O • Ca2Si + Cl2 → CaCl2 + SiCl4 Ca2Si + 4 Cl2 → 2 CaCl2 + SiCl4 • Si + CO2 → SiC + SiO2 2 Si + CO2 → SiC + SiO2

  13. Group Work: Balancing Equations • 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.

  14. Balancing Act Notes • 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.

  15. Chemical Reactions Reading • You will work in groups of four or five at your table. • Fold a sheet of paper into four squares. • Label each square: • Synthesis reaction • Decomposition reaction • Single Replacement Reaction • 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.

  16. + H2 O2  H2O (g) (g) (l) H H O O H H H H H H 1. Synthesis Reactions • Two substances combine to make one • Synthesismeans “to make” O O

  17. A + B  AB SYNTHESIS Na + Cl2 NaCl

  18. NH3 (l) N2 + H2  (g) (g) 2. Decomposition Reactions • One substance breaks down into 2 • Decompositionmeans “to break down” or “decay” H H H H N N H H

  19. AB  A + B Decomposition NaCl  Na + Cl2

  20. one element replaces another in a compound 3. SINGLE REPLACEMENT AB + C  AC + B

  21. Single Replacement Reaction

  22. Single Replacement AB + C  AC + B or CB + A NaBr + Cl2 NaCl + Br2

  23. 4. DOUBLE REPLACEMENT Both elements in two compounds switch places AB + CD  AD + CB

  24. Double Replacement NaBr + Pb2S3 Na2S + PbBr3 K2SO4 + Ba(OH)2 KOH + BaSO4

  25. CH4 C2H4 + + O2 O2 CO2 CO2 + + H2O H2O   C6H12O6 + O2 CO2 + H2O  5. Combustion Reactions • A hydrocarbon reacts with oxygen gas to produce carbon dioxide and water vapor • Combustionmeans to “burn in oxygen”

  26. Exit Slip! Balance and Identify the Type of Reaction. • Mg + O2 MgO • C3H8 + O2  CO2 + H2O • Na + Cl2  NaCl • C6H6  C + H2 • FeO + CO2  FeCO3

  27. Homework • Read pp. 271-274 • Do problems pp. 271 #1-3, pp. 298 #1, 2, 3, 5, 6, 7

More Related