2Write and classify balanced chemical equations from written descriptions of reactions. Include: polyatomic ionsPredict the products of chemical reactions, given the reactants and type of reaction.Additional KEY Terms
3Chemical equation – contains all necessary info about a reaction (like a recipe). ++
4The Law of Conservation of Mass: In any chemical reaction matter cannot be created or destroyed.H2 (g) + O2 (g) H2O (g)22HHOHHOOHHHWe call this equation unbalanced because the atoms are not conserved.HO
5Balancing Rules:You cannot change the formula of any reactant or product.You can only change the coefficients in front of the reactants and products.3H2O
8+ + 2 K2O + Cl KCl + O (s) 2 2 (g) 4 2 (g) +1 -2 +1 -1 potassium Solid potassium oxide and chlorine gas react to produce potassium chloride and oxygen gas.potassiumoxidepotassiumchloride+chlorine+oxygen2K2O Cl KCl + O(s)22(g)42(g)
9Many reactions are similar. Chemists have classified the 5 types of reactions.BIG PICTURE IDEA:If you know the reactants - you can guess the type of reaction AND predict the products.
10Key Words Synthesis reactions Decomposition reactions Single replacement reactionsDouble replacement reactionsCombustion reactions
112 2 4 3 2 K + Cl2 KCl Fe + O2 Fe2O3 Synthesis Reactions (Combination): 2 or more substances react to form a single substance.A + B C2K Cl KClFe O Fe2O32432
12C A + B 2 2 2 3 CO2 CO + O2 Al2S3 Al + S Decomposition Reactions: A single compound splits apart, into two or more simpler compounds.C A + BCO CO O2Al2S Al S2223
13A + BC AC + B 2 2 2 2 Single Replacement Reactions: One element replaces another element in a compound.More active elements replace less active elements.A + BC AC + B22I CuCl Cl CuIBa K(NO3) K Ba(NO3)222
14AB + CD AD + CB 2 2 3 3 BaF2 + LiBr BaBr2 + LiF Double Replacement Reactions:2 compounds split and exchange positive ionsAB + CD AD + CB22BaF LiBr BaBr LiFHCl AlBr3 HBr AlCl333
15CxHy + O2 CO2 + H2O 8 7 3 5 3 4 C7H6O + O2 CO2 + H2O Combustion Reactions:Oxygen reacts with a carbon compound to produce water, carbon dioxide and heat.CxHy + O2 CO H2OC7H6O O CO H2OC3H O CO H2O873534
16Synthesis or combination A + B C Decomposition C A + BSingle replacement A + BC B + ACDouble replacement AC + BD AD + BCCombustion reactions CxHy + O2 CO2 + H2O
17CAN YOU / HAVE YOU?Write and classify balanced chemical equations from written descriptions of reactions.Include: polyatomic ionsPredict the products of chemical reactions, given the reactants and type of reaction.