Presentation on theme: "J Unit 3. Chemical Reactions 3.3 How do we balance a chemical reaction? February 8, 2010 DO NOW: MR #3 An element that has a low first ionization energy."— Presentation transcript:
J Unit 3. Chemical Reactions 3.3 How do we balance a chemical reaction? February 8, 2010 DO NOW: MR #3 An element that has a low first ionization energy and good conductivity of heat and electricity is classified as a (1) metal (3) nonmetal (2) metalloid (4) noble gas AIM: How do we balance chemical reactions in order to obey the law of conservation of mass? CHOICELOW IONIZATION ENERGY?GOOD CONDUCTIVITY OF HEAT AND ELECTRICITY? METAL NONMETAL METALLOID NOBLE GAS Check the TABLE S LOW Periodic Trends? YESTHINK: copper wires HIGH NO SOME HIGH SOME LOWSOME YES SOME NO These are nonmetals already….dont waste your time!
HOW DO WE BALANCE EQUATIONS? Step 1. Check that an equal amount of an element appears in the reactants that does in the products C(s) + O 2 (g) CO 2 (g) ElementReactantsProducts Step 2. If not equal add coefficients C O Step 3. Check that the equation is balanced after you add coefficients. THIS IS A BALANCED EQUATION
LETS TRY SOME H 2 (g) + O 2 (g) H 2 O(g) ElementReactantsProducts H O Not equal so we must add COEFFICIENTS! x 2 2 = 4 = 2 x 2= 4
LETS TRY SOME KClO 3 KCl+O 2 ReactantsProducts K Cl O x 2 x 3 = 6 23 x 2 = 2 2 x 2 = 2
Complete the Independent Practice -IP will be collected at the end of class!!! -WORK ON UNIT 1 in your HOMEWORK PACKET -UNIT 1 completion will be check on Monday at the beginning of class