Mastering Chemical Reactions: A Comprehensive Guide

1. CH.7 REVIEW! Taught by Lindsey Coyle and hunter colon

2. CHEMICAL REACTIONS 7.1 • Chemical reactions always involve changing substances the reactants change into one or more substances, or products. • Reactants Products • The bonds hold the atoms together but break and form again in a different way. This is the law of conservation of mass. • Mass is neither created nor destroyed during the process

3. WRITING CHEMICAL EQUATIONS 7.2 • In chemical equations an arrow separates the formulas of the reactants (on left) from the formula of the product (on right) • Ex: Fe+O2 Fe2O3 • Skeleton Reaction- Chem equation that does not indicate the relative amounts of the reactants and products. • Catalyst- A substance that speeds up a reaction without being used up • Ex: H2 O2 (aq) MnO2 H2O(l)+ O2 (g) • To Indicate the physical state (s) for solid, (l) for liquid, and (g) for gas, (aq) for substance dissolved in water.

4. BALANCING EVERYDAY EQUATIONS 7.3 • You can write word equations similar to chemical equations for everyday processes. • Ex: Forwards+Guards+Center Basketball Team • F+G+C F2 G2 C (unbalanced) • ^does not indicate the number of people needed for each position in the product. You need coefficients. Balanced Equation: F2 + G2 + C F2G2C

5. TRY IT ON YOUR OWN! • Make an equation for an average summer outfit! • Hint: (flip flops (2), t-shirt, and shorts) If you guessed F + T + S FTS Correct!

6. Balancing Chem Equations 7.4 • Balancing chem equations so its quantitatively correct. • In balanced equations each side of the equation has the same number of atoms of each element. • Atoms only rearranged.

7. Types Of Reactions 7.5 • 5 Types • Combination 7.6- two or more substances react to form a single substance • Decomposition 7.7- a single compound is broken down into two or more products • Decomposes into two simpler compounds. • Requires energy from heat, light, or electricity.

8. Continued… • Single-Replacement 7.8- Atoms of an element replace the atoms of a second element in a compound • Double-Replacement 7.9- Involves an exchange of positive ions between two compounds Usually between two ionic compounds in an aqueous solution.

9. Combustion 7.10 • An element or compound reacts with oxygen often producing energy in the form of heat and light.

10. Predicting Products of a Chemical Reaction 7.11 • You must recognize the possible type of reaction that the reactants can undergo • Remember! • Combination=Combine chemically to form new compound. 2 elements, 2 compounds, at least one a molecular compound • Decomposition=Decomposed into two or more elements or compounds. A single binary compound a single ternary compound • Single-Replacement=element replaces another element from a compound aqueous solution. An element and a compound • Double-Replacement=2 ionic compounds react by exchanging cations to form two different compounds. • Combustion=Reaction with oxygen to produce carbon dioxide and water. Oxygen and a compound of C or H

11. PRACTICE: *BALANCE THIS EQUATION AND IDENTIFY THE TYPE OF REACTION! ___ NaBr + ___ Ca (OH)2 ___ CaBr2 +___NaOH • 2,1,1,2 Double Replacement • 1,2,3,1 Single Replacement • 1,2,1,3 Combination Reaction • 3,4,2,1 Combustion Reaction

12. HOMEWORK! • Write the word equations below as chemical equations and balance • Zinc and lead (11) • Hydrogen gas and nitrogen monoxide

13. http://www.creative-chemistry.org.uk/funstuff http://serendip.brynmawr.edu/sci_edu/chemsites.html www.teachersdomain.com http://www.sciencekids.co.nz/ Helpful Websites:

14. Thanks For Watching 