Types of Chemical Reactions

The word “synthesize” means to produce. Synthesis Reactions A + B  AB The word “synthesize” means to produce. How to identify: 2 elements  one product.

Synthesis Reaction Ex. 4Fe + 3O2  2Fe2O3 Iron + Oxygen  Iron (III) Oxide

Decomposition Reactions AB  A + B How to identify: they always have only one reactant.

Decomposition Rxn. Ex. H2CO3  CO2 + H2O Carbonic acid  Carbon dioxide + Water

A single metal replaces another one in a compound. Single Replacement A + BC  AC + B A single metal replaces another one in a compound.

Double Replacement AB + CD  AD + CB The metals in two compounds switch places. (2 compounds  2 new compounds)

An organic compound is any compound containing C, H, and sometimes O. Combustion Organic cmpd. + O2  CO2 + H2O An organic compound is any compound containing C, H, and sometimes O.

Predicting Products of Reactions

Write the formula correctly by balancing charges. Synthesis Two elements  Write the formula correctly by balancing charges.

Synthesis cont... Nonmetal oxide + water  Acid Combine atoms from both reactants. Start acid formula with H.

Decomposition Binary Compound  Break into elements.

Decomposition cont... Metal Carbonate  Metal oxide + CO2

Single Replacement Metal + Compound(aq)  Use “activity series” If the lone metal is higher than the one in the compound there will be a reaction. If not, write “N.R.” in the products.

Ex. 2Al(s) + 3Pb(NO3)2(aq)  3Pb(s) + 2Al(NO3)3(aq) Al is more reactive (“fun”) and kicks Pb out of the “friendship”

Compound(aq) + Compound(aq)  Double Replacement Compound(aq) + Compound(aq)  Use the Solubility Table from your book. If both products are SOLUBLE, write “N.R.” in the products.

Completely perfect combustion, but not reality. Organic + O2  CO2 + H2O Completely perfect combustion, but not reality.

Reactions in Aqueous Solution

Ions in Solution When ionic compounds dissolve in water they break apart: “NaCl(aq)” means Na+(aq) + Cl-(aq) “CaCl2(aq)” means Ca+2(aq) + 2Cl-(aq)

Ionic Equations Becomes In a “complete ionic equation” you split the aqueous compounds into their ions: NaCl(aq) + AgNO3(aq) NaNO3(aq) + AgCl(s) Becomes Na+(aq) + Cl-(aq) + Ag+(aq) + NO3-(aq)  Na+(aq) + NO3-(aq) + AgCl(s)

Ionic Equations Some of the ions don’t change from one side to the other (Na+ and NO3-). They are “spectator ions”.

Ag+(aq) + Cl-(aq)  AgCl(s) Net Ionic Equations “Net” means “after adjustments and deductions”. Writing the net ionic equation you leave the spectator ions out. Ag+(aq) + Cl-(aq)  AgCl(s)

Examples Balance these, then write the complete ionic equation: Pb(ClO4)2(aq) + NaI(aq) PbI2(s) + NaClO4(aq) Zn(s) + HCl(aq)  ZnCl2(aq) + H2(g)

Examples Now give the net ionic equation of the two reactions. Pb+2(aq) + 2I-(aq)  PbI2(s) Zn(s) + 2H+(aq)  Zn+2(aq) + H2(g)

Keep in Mind When you have the SAME coefficient for ALL of the reactants AND products, reduce them to ONE.