Balancing Chemical Equations

Writing Word Equations Steps in writing equations: 1.word equation A.types of reactions B.predicting products 2.formula equation (unbalanced) 3.balanced chemical equation 4.net ionic equation (for precipitation reaction)

Types of Chemical Reactions

1. Synthesis 2. Decomposition 3. Single Replacement 4. Double Replacement 5. Combustion A + B → AB AB → A + B AB+ C → AC + B AB+ CD → AD + CB CH+ O 2 → CO 2 + H 2 O (N.B., in a double replacement, cations stay in front)

Examples of Chemical Reactions 1. Synthesis 2. Decomposition 3. Single Replacement 4. Double Replacement 5. Combustion 2H 2 O → 2H 2 + O 2 2Al + 3CuCl 2 → 2AlCl 3 + 3Cu AgNO 3 + NaCl → AgCl + NaNO 3 1C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O 2H 2 + O 2 → 2H 2 O (cellular respiration)

Types of Chemical Reactions 1. Synthesis 2. Decomposition 3. Single Replacement 4. Double Replacement 5. Combustion A + B → AB AB → A + B AB+ C → AC + B AB+ CD → AD + CB CH+ O 2 → CO 2 + H 2 O N.B. A.“replacement” or “displacement” B.in a double replacement, cations stay in front C.subtypes – e.g,. 2NaCl + 1F 2  2NaF + 2Na is a halogen s.r. reaction

Steps to completing a balanced chemical equation. Given words of reactants. 1.Determine the type of reaction. 2.Write the words for the products. (even when given the reactants formulas) 3.Translate the words into formulas. 4.Balance 5.Check

Ag + CuSO 4 1.Single replacement (cation replacement) 2.Ag + CuSO 4  copper + silver chloride (Silver is +1) 3.Ag + CuSO 4  Cu + AgCl 4.1Ag + 1CuSO 4  1Cu + 1AgCl