Types of Reactions

Synthesis

• Atoms, molecules or compounds bond together to produce a larger compound.

A + B AB

Synthesis

Na + Cl NaClSodium + chlorine sodium chloride

HCl + NH3 NH4Clhydrochloric acid + ammonia ammonium chloride

Decomposition

• Larger compounds break down into elements, molecules or compounds.

AB A + B

Decomposition

CaBr2 Ca + Br2

Calcium bromide calcium + bromine

NH4NO3 N2O + 2 H2Oammonium nitrate nitrous oxide + water

Displacement Reactions• Recall: Ionic compounds: metal + nonmetal

• In displacement reactions: - Metals can displace metals. - Nonmetals can displace nonmetals.

* Hydrogen: because it’s a nonmetal with a “+” charge it can displace (and be displaced) by metals.

Single Displacement

• Only ONE element or polyatomic ion is displaced.

AB + M MB + A

AB + N AN + B

A & M are metals

B & N are nonmetals

Single Displacement

2AgNO3 + Mg Mg(NO3)2 + 2AgAB M MB A

CaI2 + Br2 CaBr2 + I2

AB N AN B

Single Displacement

Double Displacement

• TWO elements or polyatomic ions are displaced.

AB + MN AN + MB

A & M are metalsB & N are nonmetals

Double Displacement

Pb(NO3)2 + 2KI PbI2 + 2KNO3

AB MN AN MB

CaCO3 + HCl H2CO3 + CaCl2

AB MN AN MB

Double Displacement

Double Displacement

Two things can occur:1. Acid + base produces a

salt and water.

2. A solid/precipitate forms in the solution.

Combustion

• A hydrocarbon reacts with oxygen.

Combustion

Complete Combustion• A large supply of oxygen is available.

Hydrocarbon + oxygen carbon dioxide + water (+ energy)

Combustion

Incomplete Combustion• Poor supply of oxygen.

Hydrocarbon + oxygen carbon dioxide + carbon monoxide + carbon + water (+ energy)

Terminology

• (g) for “gas”

• (l) for “liquid”

• (aq) for “aqueous” (water solution)

• (s) for “solid” or “precipitate”

Pb(NO3)2 (aq) + 2KI (aq) PbI2 (s) + 2KNO3 (aq)