Naming Formulas Percent composition Empirical formulas Balancing Equations Types of Reactions Activity Series

Test 4 Review

A molecule is held together by covalent bonds.

Valence electrons are shared. Between non-metals i.e. H2O, CO2, O2, NO

Molecular Compounds

Use prefixes 1 mono-2 di-3 tri-4 tetra-5 penta-6 hexa-7 hepta-8 octa-9 nona-10 deca-

Naming molecular compounds

Use prefixes 1 mono-2 di-3 tri-4 tetra-5 penta-6 hexa-7 hepta-8 octa-9 nona-10 deca-

Naming molecular compounds

Determine the mass percentage of each element in the compound.

Mass of element x 100% mass of compoundWhat is the percent composition of Fe2O3?2 Fe 2 x 55.8 = 111.63 O 3 x 16.0 = 48.0Formula mass 159.6%Fe = 111.6/159.6 = 70.0%% O = 48.0/159.6 = 30.0%

Percent Composition

X (empirical formula) = molecular formula

so x = molecular formula mass empirical formula mass

Calculating Molecular Formula

What is the molecular formula of the molecule that has an empirical formula of CH2O and a molar mass of 120.12 g/mol?

Empirical formula mass: 12.0 + 2.0 + 16.0 = 30.0 amuX = 120.12 amu = 4 30.0 amu

So C4H8O4 is the molecular formula.

Find the empirical formula of a compound that contains 53.7% iron and 46.3% sulfur.

% composition g mass of 100 g sample g moles g mole ratio

53.7g x 1 mol/55.8g = .962 mol Fe 46.3g x 1 mol/32.1g = 1.44 mol S .962/.962 = 1, 1.44/.962 = 1.5 1:1.5 ratio x 2 = 2:3 ratio Fe2S3

Determining empirical formula

“Honkle Brif” H2

O2

N2

Cl2 Br2

I2 F2

Diatomic Molecules

Yields Gas (g) Precipitate Solid (s) or down arrow Liquid (l) Aqueous (aq)

Symbols

Balancing Equations

Synthesis (Combination) Decomposition Single Displacement (Replacement) Double Displacement (Replacement) Neutralization Combustion

Types of Reactions