Chem Catalyst1) Balance the following:

Cu(s) + S(s) Cu2S(s)

Be(s)+ O2(g) BeO(s)

K(s) + Cl2(g) KCl(s)

2) What do these equations have in common?

Today’s Agenda:1. Catalyst2. Notes: Types of Chemical Reactions3. Reaction analogies4. P. 339 #24

Unit 5: Chemical Reactions BIG Questions

1. How does a chemical equation represent a chemical reaction?

2. Why do chemical reactions occur?

3. Why is balance essential when working with chemical reactions?

Combination (Synthesis)- Two or more substances combine to form a

single compound- A + B AB- 2 Reactants, 1 Product

- Ex: 2 Zn + O2 2 ZnO

Decomposition Reaction- A single compound splits into two (or more)

substances- XY X + Y- 1 Reactant, 2 Products

- Ex: 2HgO (s) 2Hg(l) + O2(g)

Single-Replacement Reaction- An element replaces one of the ions in an ionic

compound- A + BC AC + B- 2 Reactants, 2 Products

- Ex: Cu(s) + AgNO3(aq) Ag(s)+ CuNO3(aq)

Double-Replacement Reaction- Ionic compounds exchange cations to form new

ionic compounds- AB + XY AY + XB- 2 Reactants, 2 Products

- Ex: FeCl3 + 3 NaOH Fe(OH)3 + 3 NaCl

Combustion- A hydrocarbon reacts with oxygen to form

carbon dioxide and water- CxHyOz + O2 CO2 + H2O

- 2 Reactants (hydrocarbon & O2), 2 Products (CO2, H2O)

- Ex: C2H5O (l) + O2 (g) CO2 (g) + H2O (l)

Examples:2 C8H18 (l) + 25 O2 (g) 16 CO2 (g) + 18 H2O (l)

2HgO(s) 2Hg(l)+ O2(g)

CaI2 + Hg(NO3)2 HgI2 + Ca(NO3)2

2Mg + O2 2MgO

Fe(s) + Pb(NO3)2(aq) Pb(s) + Fe(NO3)2(aq)