Practical Investigation: Chemical Titration
The experiment preformed an acid-base titration; which is a neutralisation reaction.
Titration is the addition of a solution of a known concentration, known as a titrate (Sodium
hydroxide), into a s
Adsorption chromatography: adsorption = attachments of molecules to a surface of a solid
Secondary interactions form between molecules of atoms on surface of solid
The stronger the secondary interaction the stronger the adsorption.
Energy is the capacity for doing work. For example: to carry out some sort of task- the capacity to do
The energy from reactions comes from the breaking and forming of bonds between atoms.
When chemical bonds are formed energy
Liquids and Solids
Forces between (rather than within) molecules.
dipole-dipole attraction: molecules with dipoles orient themselves so that
+ and ends of the dipoles are close to each other.
hydrogen bonds: dipole-dipole attraction
Free Energy and Electrodes
Free Energy and Cell Potential
G = nFE
n = number of moles of electrons
F = Faraday = 96,485 coulombs per mole
This equation states that the maximum cell potential is directly related
to the free energy difference b
Determining the Formula of a compound
If we know the % composition we can find
the formula. Molecular formula = (empirical formula)n where
Empirical formula = CH = simplest formula
Molecular formula = (CH)6 = C6H6
For some compounds (like H2O, N
Units of Measurement
Measurements mass, length, time, temperature etc.
Different systems were adopted in different parts of the world.
In 1960, an international agreement set up a system of units called the
The Localized Electron Model
A complex ion with a coordination number of 6 will have an octahedral
arrangement of ligands and complexes with two ligands will be linear.
Complex ions with a coordination number of 4 can be either tetrahedral or
The study of carbon-containing compounds and their properties.
The vast majority of organic compounds contain chains of rings of carbon
. . . compounds composed of carbon and hydrogen.
Saturated: carbon-carbon bonds a
A virtually inexhaustible supply of hydrogen exists in the waters of the
However, the reaction H2O(l) H2(g) + 1/2O2(g), requires 286 kJ of energy
per mole of liquid water, large-scale production of hydrogen from water is
Group 3 and 4 Elements
Group 3A Elements
Valence electron configuration ns2np1.
Increase metallic character in going down the group.
B is a nonmetal and its compounds are covalent.
Boranes are hydride of B: diborane B2H6
Al is the most abundant metal on e
A GasUniformly fills any container
Mixes completely with any other gas
Can easily be compressed
Exerts pressure on its surroundings
The properties of a gas depends upon four variablesPressure (P)
Is equal to force/unit area
Measured by a barometer
Alkenes and Alkynes
Alkenes: hydrocarbons that contain a carbon-carbon double bond.
Alkynes: hydrocarbons containing a carbon-carbon triple bond.
Nomenclature for Alkenes
Root hydrocarbon name ends
Example: What volume of 16 M sulfuric acid
must be used to prepare 1.5 L of 0.10 M H2SO4
V1 = Volume before dilution = ?
M1 = Concentration before dilution = 16 M
V2 = Volume after dilution = 1.5 L
M2 = Concentration after dil
The overall reaction is split into two half-reactions, one involving
oxidation and one reduction.
8H+ + MnO4 + 5Fe2+
Mn2+ + 5Fe3+ + 4H2O
Fe2+ is oxidized and MnO4- is reduce. Electrons are transferred from
Fe2+ (reducing agen
Specific Heat Capacity: The energy required to raise the temperature of
one gram of a substance by one degree celsius (J/oC.g).
Molar Heat Capacity: The energy required to raise the temperature of one
mole of a substance by one degree celsiu
For the first row transition metals 3d orbitals begin to fill after the 4s orbital
Sc:[Ar]4s23d1, Ti: [Ar]4s23d2, V: [Ar]4s23d3, Cr: [Ar]4s23d4
(expected), [Ar]4s13d5 (actual).
Chromium configuration occurs because the
Covalent vs Polar Covalent Bonds
When electrons are shared by nuclei and forms bond then the bond known
as covalent bond.
H2 molecule: electrons reside primarily in the space between the two
nuclei, attracted by both protons. The potential e
Rules Governing Formal Charge
To calculate the formal charge on an atom:
Take the sum of the lone pair electrons and one-half the shared electrons.
This is the number of valence electrons assigned to the atom in the
Subtract the nu
Changes in a System
Le Chteliers Principle
. . . if a change is imposed on a system at equilibrium, the position of
the equilibrium will shift in a direction that tends to reduce that change.
Effects of Changes on the System
1. Concentration: The system w
When dissolved in water produce a solution containing free H+ ions
An acid is a molecule with one or more H+ ions attached to an anion
If the anion does not contain oxygen, the acid is named with the prefix
hydro and the
In going from a particular set of reactants to a particular set of products, the
change in enthalpy is the same whether the reaction takes place in one
step or in a series of steps.
N2(g) + 2O2(g)
H1 = 68 kJ