1. 13/11/2018
Chemistry in Action
Mr Ronesh
British School in Baku

2. Simple formulae to learn
13/11/2018
Covalent formulae
Ionic formulae
H2O
CO2
NH3 H2 O2 N2
SO2
Water
Carbon dioxide
Ammonia
Hydrogen
Oxygen
Nitrogen
Sulphur dioxide
NaCl
CaCl2
MgO
HCl
H2SO4
HNO3
NaOH
Ca(OH)2
CaCO3
Al2O3
Fe2O3
Sodium chloride
Calcium chloride
Magnesium oxide
Hydrochloric acid
Sulphuric acid
Nitric acid
Sodium hydroxide
Calcium hydroxide
Calcium carbonate
Aluminium oxide
Iron oxide

3. Some more obvious ones:
13/11/2018
Some more obvious ones:
Sulphur
Chlorine
Argon S Cl Ar
18) Calcium
19) Zinc Ca Zn
The less obvious ones:
Sodium
Potassium
Iron
Copper
Silver Na K Fe Cu Ag
6) Tin
7) Gold
8) Mercury
9) Lead Sn Au Hg Pb

4. Sodium + water sodium hydroxide + hydrogen
Balancing equations
13/11/2018
Consider the following reaction:
Sodium + water sodium hydroxide + hydrogen
Na + H2O NaOH + H2 Na O H O H Na + H +
This equation doesn’t balance – there are 2 hydrogen atoms on the left hand side (the “reactants” and 3 on the right hand side (the “products”)

5. Balancing equations We need to balance the equation:
13/11/2018
We need to balance the equation:
Sodium + water sodium hydroxide + hydrogen Na O H O H Na O H Na O H + H + Na
Now the equation is balanced, and we can write it as:
2Na(s) + 2H2O(l) NaOH(aq) + H2(g)

6. Some examples 2 2 3 2 3 Mg + O2 Zn + HCl Fe + Cl2 NaOH + HCl CH4 + O2
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Mg O2
Zn HCl
Fe Cl2
NaOH HCl
CH O2
Ca H2O
NaOH H2SO4
CH3OH O2
MgO
ZnCl H2
FeCl3
NaCl H2O
CO H2O
Ca(OH) H2
Na2SO H2O 2