MIDTERM REVIEW IN FOUR PARTS

CHEMICAL REACTIONS: relate how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions. Identify the reactants and products in a chemical equation. Write a balanced chemical equation when given the names or formulas of all the reactants and products in a chemical reaction. Classify a reaction a synthesis, decomposition, single replacement, double replacement, or combustion. Correctly use the activity series for metals and nonmetals in a single replacement reaction. Predict the products of double replacement, combustion, and single replacement reactions. CHEMICAL REACTIONS

Identify the reactants and products in a chemical equation. REACTANTS  PRODUCTS Examples: Iodine crystals react with chlorine gas to produce iodine trichloride. Calcium hydroxide is produced when calcium oxide reacts with oxygen CHEMICAL REACTIONS

Balance metals, then nonmetals, 1. Write the chemical equation for the reaction. 2. Count the number of atoms of each element on both sides of the arrow. 3. Balance the equation using coefficients. Balance metals, then nonmetals, then hydrogen, then oxygen 4. Check your work by recounting the number of atoms on each side of the arrow. CHEMICAL REACTIONS

CHEMICAL REACTIONS RULES TO FOLLOW Change coefficients only. Never change a symbol, formula, or subscript. Place coefficients in front of the entire chemical formula. CHEMICAL REACTIONS

Write the correct formulas for each of the chemicals named Write the correct formulas for each of the chemicals named. Determine which are the reactant(s) and which are the product(s). Write out the chemical equation for the reaction. Count the number of atoms of each element on both sides of the arrow. Balance the equation using coefficients Check your work by recounting the number of atoms on each side of the arrow. CHEMICAL REACTIONS

CH4(g) + 2O2(g)  CO2(g) + 2H2O(g) 1. SYNTHESIS Reaction What to look for: ONE PRODUCT 2Mg(s) + O2(g)  2MgO(s)   2. DECOMPOSITION Reaction What to look for: ONE REACTANT H2CO3(aq)  H2O(l) + CO2(g) 3. COMBUSTION What to look for: REACTANT of HYDROCARBON and OXYGEN and PRODUCTS OF CO2 and H2O CH4(g) + 2O2(g)  CO2(g) + 2H2O(g) CHEMICAL REACTIONS

CHEMICAL REACTIONS 4. SINGLE REPLACEMENT Reaction What to look for: UNCOMBINED ELEMENT ON EACH SIDE Mg(s) + 2HCl(aq)  MgCl2(aq) + H2 Cl2(g) + 2 NaBr(aq)  2NaCl(aq) + Br2(g) 5. DOUBLE REPLACEMENT Reaction (or double displacement reaction) What to look for: TWO COMPOUNDS ON BOTH SIDES HCl(aq) + NaOH(aq)  NaCl(aq) + H2O(l) CHEMICAL REACTIONS

Activity Series Li K Ba Sr Na Ca Mg Al Mn Zn Cr Fe Cd Co Ni Sn Pb H Sb As Bi Cu Hg Ag Au NON Metal Activity Series F O Cl Br I SINGLE REPLACEMENT PREDICTION 1. Active metals replace less active metals or hydrogen from their compounds in an aqueous solution. Use the metal activity series to determine if it will replace something in the compound. Mg (s) + FeCl3(aq)  2. Active nonmetals replace less active nonmetals from their compounds in an aqueous solution. Use the nonmetal activity series to determine if it will replace something in the compound. Cl2(g) + KI(aq)  CHEMICAL REACTIONS

CHEMICAL REACTIONS DOUBLE REPLACEMENT PREDICTION: Formation of a precipitate, gas, or molecular substance (usually water). KI (aq) + Pb(NO3)2 (aq)  HCl(aq) + K2CO3(aq)  LiOH(aq) + HBr(aq)  CHEMICAL REACTIONS

CHEMICAL REACTIONS COMBUSTION PREDICTION There will always be a hydrocarbon (carbon and hydrogen compound) and oxygen gas forming carbon dioxide and water. C2H8 (g) + O2 (g)  CHEMICAL REACTIONS

MIDTERM EXAM 46 Multiple Choice questions (Part One) Short Answer (Part Two) Density problem (I will not give you the formula). Given an element on the periodic table, be able to give information about its characteristics just by looking at the periodic table (just like review table). Molecular Geometry table (just like review table). Balance two chemical equations. Extra Credit will be on this part of the test. MIDTERM EXAM