chemistry is the study of matter and the changes it undergoes
matter is anything that occupies space and has mass
classification of matter :
a) pure substance
              a.1) element
              a.2) compound
b) mixture
              b.1) homogeneous mixture
              b.2) heterogeneous mixture

scientific purposes :        STP is specified as conditions at 32oF & 14.7 psia
fuel gases :                    STP is specified as conditions at 60oF & 14.7 psia

its symbol is mol
Avogadro's number = 6.022045 X 10 23
1 mol = 6.022045 X 10 23 particles
molar mass is the mass of substance that contains 1 mole of the substance
molar volume is the volume occupied by 1 mole of any gases
1 mole of an ideal gas occupies 22.414 dm 3 @ 22.414 L at STP

eg. O is 16 times heavier than 1/12 carbon-12, thus its relative atomic mass is 16
eg. O2 is 32 times heavier than 1/12 carbon-12, thus its relative molecular mass is 32

eg. glucose
its empirical formula is CH2O
its molecular formula is C6H12O6

each column is called a group
each row is called a period
atomic number is the number of proton(s) or electron(s) in a NEUTRAL atom

some selection :
name symbol atomic number electron arrangement
carbon C 6 2.4
oxygen O 8 2.6
sodium Na 11 2.8.1
magnesium Mg 12 2.8.2
aluminium Al 13 2.8.3
chlorine Cl 17 2.8.7
potassium K 19
iron Fe 26
cobalt Co 27
copper Cu 29
tin Sn 50
mercury Hg 80
lead Pb 82

antimony = stibium (Sb)
copper = cuprum (Cu)
gold = aurum (Au)
iron = ferrum (Fe)
lead = plumbum (Pb)
mercury = hydrargyrum (Hg)
potassium = kalium (K)
silver = argentum (Ag)
soldium = natrium (Na)
tin = stannum (Sn)
tungsten = wolfram (W)

some common examples :
name1 symbol name2
iron (III) Fe3+ ferric
iron (II) Fe2+ ferrous
copper (II) Cu2+ cupric
copper (I) Cu+ cuprous
cobalt (III) Co3+ cobaltic
cobalt (II) Co2+ cobaltous
tin (IV) Sn4+ stannic
tin (II) Sn2+ stannous
lead (IV) Pb4+ plumbic
lead (II) Pb2+ plumbous
mercury (II) Hg2+ mercuric
mercury (I) Hg22+* mercurous
*mercury (I) ions always occur bound together to form Hg2

ionic bonding is formed by transfer of electron(s) from metal atom(s) to non-metal atom(s)
eg. NaCl
covalent bonding is formed by sharing of electron(s) between non-metal atoms
eg. CH4 , CO2 , O2

eg. CH4 + O2 ---> CO2+ H2O
CH4 :      C(-4x1) H(+1X4)
O2 :        covalent bonding
CO2 :      C(+4x1) O(-2X2)
H2O :      H(+1x2) O(-2X1)

it is the quantitative study of products and reactants in chemical reactions
eg. methanol (CH3OH) burns in air according to the equation 2CH3OH + 3O2 ---> 2CO2 + 4H20
if 209 g of methanol are used up in the combustion, what is the mass of water produced ?
molecular mass of CH3OH = 12 + (1x3) + 16 + 1 = 32 g
mole of CH3OH = 209 / 32 ≈ 6.53 mol
by ratio, mole of H20 ≈ 6.53 X 2 ≈ 13.06 mol
molecular mass of H20 = (1X2) + 16 = 18 g
mass of H20 being produced ≈ 13.06 X 18 ≈ 235 g

cathode = the negative electrode
anode = the positive electrode
cation = the positive ions that move towards the cathode
anion = the negative ions that move towards the anode
eg. in a molten NaCl, there are Na+ and Cl-
at cathode ( reduction - receiving electron ) :
2Na+ + 2e- ---> 2Na(l)
at anode ( oxidation - releasing electron ) :
2Cl- ---> Cl2(g) + 2e-
the overall process is : 2Na+ + 2Cl- ---> 2Na(l) + Cl2(g)

the term redox comes from reduction and oxidation
redox reaction is a reaction involving reduction and oxidation simultaneously
reduction & oxidation can be defined as :
       1) gain / loss of oxygen & hydrogen
       2) gain / loss of electron
       3) increase / decrease in oxidation number
eg 1 :     H2O(g) + Mg(s) ---> MgO(s) + H2(g)
             H2O being reduced to H2              LOSS OF OXYGEN
             Mg being oxidized to MgO            GAIN OF OXYGEN
eg 2 :     Pb(s) + O2(g) ---> 2PbO(p)
             O2 being reduced to 2O2-             GAIN OF ELECTRON
             Pb being oxidized to Pb2+             LOSS OF ELECTRON
eg 3 :     2FeCl3(aq) + SnCl2(aq) ---> 2FeCl2(aq) + SnCl4(aq)
             Fe3+ being reduced to Fe2+           DECREASE IN OXIDATION NUMBER
             Sn2+ being oxidized to Sn4+          INCREASE IN OXIDATION NUMBER

K     Na     Ca     Mg     Al     C     Zn     H2     Fe     Sn     Pb     Cu     Hg     Ag     Au    
-----<-----more reactive-----<-----

K     Na     Ca     Mg     Al     Zn     Fe     Sn     Pb     H2     Cu     Hg     Ag     Au    
----<-----more electropositive-----<----
more electropositive = higher tendency to release electron and become cation

K     Na     Ca     Mg     Al     Zn     Fe     Sn     Pb     H2     Cu     Hg     Ag     Au    
+1     +1     +2     +2     +3     +2     +2     +2     +2     +1     +2     +2     +1     +2    
----<---stronger reducing agent---<----        ---->---stronger oxidising agent--->----

acid-base reaction @ neutralization reaction :     acid + base ---> salt + water
acid = donor of hydrogen ions , H+
there are 2 types of acid : mineral acid & organic acid
eg. of mineral acid :
             hydrocloric acid     HCl
             sulphuric acid        H2SO4
             nitric acid              HNO3
eg. of organic acid :
             ascorbic acid     C6H8O6
             citric acid          C6H8O7
             malic acid         C4H6O5
             tartaric acid       C4H6O6
base = donor of hydroxide ions , OH-
alkali = base that is soluble in water ; most base are alkali
eg. of base :
             copper (II) oxide        CuO
             iron (III) oxide           Fe2O3
             lead (II) hydroxide      Pb(OH)2
eg. of alkali :
             sodium hydroxide                    NaOH
             potassium hydroxide                KOH
             aqueous solution of ammonia    NH3 (aq)
the units of concentration : g dm-3 @ mol dm-3
strong acid has high degree of dissociation in water to produce H+
strong alkali has high degree of dissociation in water to produce OH-
eg. of strong acid are HCL , H2SO4 , HNO3
eg. of strong alkali are NaOH , KOH

classification of hydrocarbons :
             a) aliphatic (without benzene ring)
             b) aromatic (with one or more benzene rings)
                          b.1) alkanes , CnH2n+2 where n = 1, 2, ..........
                          b.2) alkenes , CnH2n where n = 2, 3, ..........
                          b.3) alkynes , CnH2n-2 where n = 2, 3, ..........
the first 10 alkanes :
             methane CH4
             ethane C2H6
             propane C3H8
             butane C4H10
             pentane C5H12
             hexane C6H14
             heptane C7H16
             octane C8H18
             nonane C9H20
             decane C10H22

return to main page