Reversible reaction and equilibrium
A reversible reaction is a reaction that may proceed in either direction (forward
or reverse), depending the applied conditions.
Double arrow (
) indicates that both the forward and reverse reactions are
States of Matter
Matter is made up of very small particles and may exist in three states: solids,
liquids and gases.
The arrangements of particles in solid, liquid and gas are as follows:
Characteristics that distinguishes the three states of matter are:
Group II elements
The elements of Group II are often called the alkaline earth metals.
The Group II elements magnesium to barium are typical metals with high
melting points and good conductivity of heat and electricity.
The alkaline earth metals are silve
All chemical substances contain energy in the form of chemical energy.
Energy cannot be destroyed or created but transferred between the systems
and the surroundings.
Chemical reactions are often accompanied by transfers of energy to o
The rate of a chemical reaction is measured by the amount (in moles) of a
reactant used up in a given time. Chemical kinetics is the study of rates of
Rate of reaction = amount of reactants consumed (or products forme
Group VII elements
The halogens chlorine, bromine and iodine are covalent diatomic molecules at
room temperature. They become increasingly less volatile and more deeply
coloured on descending Group VII. Their boiling points increase as
loss of electrons. E.g. Zn Zn2+ + 2egain in oxidation number.
gain of oxygen. E.g. 2Mg + O2 2MgO
loss of hydrogen. E.g. CH3CH2OH CH3CHO + H2
gain of electrons.E.g. Cu2+ + 2e- Cu
loss in oxidation number
Very few elements around us exist as free elements. Elements tend to combine
with each other to form compounds which are naturally more stable than the free
Chemical bonds are formed which bind the different elements together.
Atoms, molecules and stoichiometry
Mass of one atom of an element
Relative atomic mass (RAM, Ar) =
Relative molecular mass (RMM, Mr) =
Relative isotopic mass =
Relative formula mass (RFM)
If an element consists of two isotopes, Y, and Z, the relative atom
An atom is the smallest particle of an element that retains the characteristics of
Elements = not separable into simpler substances.
Compounds = 2 or more elements chemically combined in fixed proportions.
Atoms of the same
Important chemistry Definition
Isotopes: - Atoms of the same element having the same atomic number but different number of protons
Mole: - (in terms of mass) One mole of any substance is its relative atomic mass or relative molecular
mass expressed in gra
ORGANIC FUNCTIONAL GROUP INTERCONVERSIONS
Hot, conc. KOH, alcoholic solution
NaOH (aq), reflux
H2SO 4, heat (1 alcohols only)
NaBH4 (aq, heat) or LiAlH4 (ether)