UNIT 6 Chemical Equations Grade: 10-12 Subject: Chemistry Date: Winter ???

Balancing Chemical Equations UNIT 6 Balancing Chemical Equations ABClark-Grubb

All chemical reactions have two parts Reactants - the substances you begin with Products - the substances produced from the reactants Reactants → Products

Which of the following substances in the reaction below are reactants? 1 Which of the following substances in the reaction below are reactants? PbCl2 + AgNO3 Pb(NO3)2 + AgCl A PbCl2 B AgNO3 C Pb(NO3)2 D AgCl

2 Which of the following substances in the reaction below are products? H2CO3 CO2 + H2O A H2CO3 B CO2 C H2O

A chemical reaction a. Atoms are joined in new ways b. Atoms are not created or destroyed. Can be described in three common ways   1. As a sentence   2. As a word equation   3. As a formula equation Copper reacts with chlorine to form copper (II) chloride. Pull copper + chlorine copper (II) chloride Pull Pull Cu + Cl2 CuCl2

Symbols used in Equations Refer to Table 11-1 p.323 the arrow separates the reactants from the products. It reads: “yields”or "produces" plus sign - “and” “combines with” “ reacts with” (s ) after the formula –solid (g ) –gas ( l ) –liquid (aq) - dissolved in water, aqueous solution.

3 What does the (g) symbol mean after a formula?

4 What does the (aq) mean after a formula?

MORE Symbols used in Equations indicates a reversible reaction 
(More later) shows that heat is 
supplied to the reaction is used to indicate the use of a 
catalyst, in this case, platinum.

What is a catalyst? A substance that speeds up a reaction without being changed by the reaction.

Skeleton Equation (unbalanced) Uses formulas and symbols to describe a 
 reaction Doesn’t indicate how many of each reactant 
 and product.

ANY QUESTIONS?