Chemical Reactions

Chemical Reactions In chemical reactions, one or more substances change into different substances.

Representing Chemical Reactions Chemists use equations to describe chemical reactions: Word equations show the name of the materials in the chemical reaction. Chemical equations show the chemical formulas of the materials in the chemical reaction. Reactants: substances that are used up during a reaction; starting substances Products: substances that are produced during a reactions; ending substances REACTANT(S)  PRODUCT(S) (Starting materials) (yields) (ending materials) (forms) (produces)

Common State Symbols in Chemical Equations Meaning Example (s) Solid Sodium chloride, NaCl(s) (l) Liquid Bromine, Br2(l) (g) Gaseous Hydrogen, H2(g) (aq) Aqueous (dissolved in water) Aqueous sodium chloride solution, NaCl(aq)

Example #1 Word equation: sodium + chlorine  sodium chloride Chemical equation: Na(s) + Cl2 (g)  NaCl(s)

Example #2 Word equation: zinc + copper (II) sulphate  zinc sulphate + copper + energy Chemical equation: Zn(s) + CuSO4 (aq)  ZnSO4 (aq) + Cu(s) + energy zinc Copper (II) sulphate Zinc sulphate copper

Consider the following reaction: AgNO3(aq) + NaCl(aq)  AgCl(s) + NaNO3(aq) Name the reactants and products in this reaction. Name the chemicals that are dissolved in water. Name the white solid. What physical properties do both reactants have in common?

Homework Worksheets: “Practice: Write the Word Equation” #1-6