Review

Various models of the atom

• Dalton’s – “billiard ball” model• Thomson – “raisin bun” model• Rutherford – “Electron Cloud” model• Bohr – best model to date

Molecular Elements

• Elements ending in –gen are diatomic.

Pg. 33 – should know this table

Changes

Pg. 47

Classifying Chemical Reactions

Pg. 58

Significant Digits

• Precision is the place value of the last measurable digit and is determined by the instrument

• 12.0 g vs 12 g vs 10 g• Non-zero numbers are significant• Zeros to the left are not significant• Zeros to the right are significant

Compounds

• Valence Electrons• Lewis Symbols• Electronegativity• Types of Bonds• Bonding Capacities

Pg. 88

Predicting Shape Summary

Rules of polar and nonpolar

Electronegativity Differences

Pg. 100

Summary

• Intermolecular forces are the attraction and repulsion of positive and negative charges

• All molecules have London forces – with momentary diploes

• Polar molecules have dipole-dipole forces• Hydrogen bonding occurs when a hydrogen is

attracted to the lone pair from an adjacent molecule

• IMF affect many various physical properties

Physical properties

• While solid has definite shape and volume; it does have various other properties that can be very different. Such as density, colour, melting points, etc

Pg. 119

Summary

Unit Test Review Summary

• Lewis Formulas• Bonding Theory (types)• Electronegativity • Molecular Formulas (Lewis, structural, sterochemical) • Bonding capacity• VSEPR• Bond and molecular Polarity• Intermolecular Forces

– Isoelectronic Compounds• Boiling points• Properties of Liquids and Solids

Units

Pg. 149

Summary

• STP: 0 ˚ C and 101.325 kPa• SATP: 25 ˚ C and 100. kPa• 101.325 kPa = 1 atm = 760 mm Hg• T (K) = t (˚ C) + 273

P= constant

P1V1 = P2V2

V1 / T1= V2/ T2

Properties of Gases• Kinetic molecular theory explains a lot about

the properties of gases– Gases are compressible - the distance between

the molecules– Gas pressure – the amount of collisions that occur– Boyle’s Law– Charles’ Law

Ideal Gas Law

• If we recall Boyle’s Law • Charles’ Law • Avogadro’s theory• Can combine all these to give:

• - constant• -universal gas constant

Solvent and Solute

• Solvent – The component of the solution present in greater amount. Solvent dissolves the solute

• Solute – The component of the solution present in lesser amount. The solute is dissolved by the solvent.

Acids and Bases

PG 199

Summary

Strength of AcidsStrong Acids: ionize (splits up into ions) almost 100% in

water mostly ions in solution amount of HCl present is negligeable

HCl(aq) H+(aq) + Cl-(aq)

Weak acids: ionize poorly in water not many of these ions present in solution mostly acetic acid (HC2H3O2)

HC2H3O2(aq) C2H3O2-(aq) + H+(aq)

NOTE: strong acids are strong electrolytes and will conductelectricity better than weak acids.

pH < 7 acidicpH = 7 neutralpH > 7 basic

• Expressing hydronium concentrations in scientific notation isn’t very convenient. The pH scale was developed to make the expression of H3O+ concentration more convenient.

• [H3O+] is the concentration in mol/L

pH = -log[H3O+]

• Back of book

Net Ionic Equations

• The chemical reaction equation can be written with just the chemicals which will react and form precipitates.

Applications of Stoichiometry

• To determine the overall experiment the percent yield is used.

• This lets us know about the experimental uncertainties– Measurements, purity, washing, estimations

Summary

Limiting Reactions

• There is only a certain amount of one of the reacting chemicals and when all of it is used up the reaction stops – this is the limiting reagent

• The other reactant is more abundant and is called the excess reagent

Limiting and Excess Reagent

• Having a reactant with excess means that more of the substance is present then required for the reaction.

• We our purposes we will use the value of 10 % for the excess amount required to make the reaction occur.

• Sample problem 8.1 pg 320

Interpreting Titration pH Curves

Pg. 334