Download Chemical Terminology

Chemical Terminology
1.0 Atomic Weight
absolute atomic mass
atomic weight
10-24 - 10-22 g
1 H-1
≡ 1,6783
1/ C-12
12
≡ 1,66053 .10-24 g
1/ C-12
12
≡ 1u
M
.10-24 g
Atom
m
=
1
12
Atom
m (C −12)
dimensionless number, weighted
g
according to the natural isotopic
fraction
mass defect
Seite 1
1.1 Natural Isotopic Fractions
natural isotopic fractions:
H-1 99,9855 %
H-2 0,0145 %
H-3 traces
O-16 99,759 %
O-17 0,037 %
O-18 0,204 %
C-12 98,892 %
C-13 1,080 %
C-14
traces
atomic
t i weights:
i ht
H: 1,0079
O:15,999
C: 12,011
1.2 Atomic Mass
relative atomic mass:
M
nuclide
=
molecular weight:
m
nuclide
1 m (C −12)
12
M
dimension less number
Not weighted according to
the natural isotopic fraction
Seite 2
molecule
=
m
molecule
1 m (C −12)
12
dimension less number
in covalent compounds
1.2.1 Examples:
H2O
CH4
SO2
O3
H2SO4
HCl
HNO3
NaOH
KOH
1,0079 . 2
1,0079 . 4
15,999 . 2
15,999 . 3
1,0079 . 2
1,0079
1,0079
1,0079
1,0079
+ 15,999
+ 12,011
+ 32,06
=
=
=
=
+ 15,999 . 4 + 32,06 =
+ 35,453
=
+ 15,999 . 3 + 14,007 =
+ 15,999
+ 22,990 =
+ 15,999
+ 39,098 =
18,0148
16,0426
64,058
47,997
98,0718
36,4609
63,0119
39,9969
56.1049
2.0 Moles
1 mol = NA particles
1 Mol He
1 Mol N2
1 Mol NaCl
AVOGADRO's
AVOGADRO
s Number NA
≡ 4,003 g
≡ 14,007 x 2
≡ 28,014 g
≡ 22,990
,
+ 35,453
,
≡ 58,443 g
12 g C
≡ 6,0221367 . 1023 C-atoms
≡ NA
Seite 3
12
[g]
6,022 ⋅10 23
= 12u
1
1u =
[g]
6,022 ⋅10 23
1C ≅
2.1 Molar Solutions
1
1/
10
5
5/
8
molar NaCl
solution
molar KCN
solution
molar CuSO4 x 5H2O
solution
molar AgNO3
solution
3.0 Chemical Reactions
Ö
Ö
Ö
Ö
Ö
Ö
photo
h t reaction
ti
surface reaction (e.g. catalysis)
polymer reaction
complex reaction
chain reaction
redox reaction
starting material
Educts
1 O2 + 1 C
Ö
final material
Products
1 CO2
stochiometrical yields
Seite 4
3.1 Redox Reactions
Na + 1/2 H2 Ö
NaH
H2
+ 1/2 O2 Ö
H 2O
B
+ 3/2 H2 Ö
BH3
Ca
+ 1/2 O2 Ö
CaO
Sr
+ H2
SrH2
S
+ O2
Ö
SO2
Ö
electron acceptance
= reduction
electron donation
= oxidation
3.1.1 Examples:
Fe / C oxidation
oxidation agents
2 Fe
C
+
+
O2 Ö
O2
Ö
3/
2
Fe2O3
CO2
Silicate reduction
reduction agents
SiO2 +
C
Ö
Seite 5
Si + CO2
3.2 Oxidation States
Electric Charge
K+, Ca2+ , Ca++, Fe3 +, Fe+++, Cl-, SO42-, SO4--, PO43-, PO4--Oxidation States
f
free
elements
l
t
monoatomic ions
oxygen in peroxides
e.g. H-O-O-H
oxidation
id ti state
t t
oxidation state
oxidation state
=0
= electric charge
= -1
3.2.1 Oxidation States
in inorganic compounds
exception?
yes
find element 1 with ENmax
oxidation state (element 1) = - valence
find element 2 with ENmin
oxidation state (element 2) = + valence
more than 3
atom types
yes
sum over all oxidation states = total charge
oxidation state (element 3) = difference
Seite 6
3.2.2 Examples 1
+1
-1
+3
-1
+1
-2
+1 +5 -2
HCl
FeCl3
H 2O
H3PO4
+1
+1
+3
+1 +3 -1
-1
NaCl
0
C60
-1
-1
NaH
BH3
NaBH4
+1
+1 +2 -3
+8/3
HCN
Fe3O4
-1
H 2O 2
-2
3.2.3 Examples 2
different oxidation states of an atom
+1 +7
-2
+4
-2
+2
+4
-2
KMnO4
MnO2
MnCO3
K permanganate
manganese
dioxide
manganese
carbonate
+1 +6
+1 +4
+1
-2
-2
-2
H2SO4
H2SO3
H 2S
sulphuric acid
sulphurous acid
hydrogen sulphide
Seite 7
4.0 Separation Processes (1)
• Adsorption
• Centrifugation and Cyclones - density differences
• Chromatography involves the separation of different dissolved
substances as they travel through a material. The dissolved
substances are separated based on their interaction with the
stationary phase.
• Crystallization
• Decantation
• Distillation - used for mixtures of liquids with different boiling points, or
for a solid dissolved in a liquid.
• Drying - removing liquid from a solid by vaporizing it
4.0 Separation Processes (2)
• Evaporation
• Extraction
• Filtration. Mesh, bag and paper filters are used to remove large
particulates suspended in fluids, eg. fly ash, while membrane
processes including microfiltration, ultra filtration, nanofiltration,
reverse osmosis
osmosis, dialysis (biochemistry) utilizing synthetic membranes
can separate micrometresised or smaller species.
• Precipitation
• Recrystallisation
• Volatile
Seite 8
Exercises
1.
2.
3.
4.
5.
6.
7.
8.
What is the molecular weight of CuSO4 x 5 H2O ?
How many atoms are in 1 g Uranium ?
How much C must be oxidized to gain 10-6 t CO2 ?
Explain the formation of SiO2 from Si and O2 using oxidation
numbers !
What are the oxidation numbers in SiHCl3 ?
How do you prepare a 0.25 m solution of sodium chloride ?
What is decantation ?
What is extraction ?
Seite 9