SIMPLE CHEMICAL EQUATIONS

If the law of conservation of matter is to be kept, it means that there must be the same number of atoms in each half of the equation. There must be the same number of atoms in reactants and in the products.

 

The law of conservation of matter states that matter is neither created nor destroyed in the course of chemical reaction. This is the main reason why the number of atoms of products must balance those of reactions and vice versa.

So, the equation:

Na+H₂O=Na0H+H₂isconsideredunbalanceandhencenotacceptable.

This has to be balanced as:

2Na+2H₂0=2Na0H _(aq)+ H_2(g)

S=solid L=Liquids Aq=aqueous g=gas

 

WRITING CHEMICAL EQUATIONS

Chemical equations are written using chemical symbols and formulae. It is necessary to have as much detail as possible about what is going on in are action e.g. hydrogen gas reacts with oxygen gas to produce water.

We translate this information to a word equation.

Hydrogen (gas)+Oxygen gas = water

(Reactants)                                       (Product)

2H₂+0₂                                      2H₂0

Balanced equation

Common chemical reactions include (a) Combustion of hydrocarbons (b) Neutralization reactions (c) Double decomposition

Examples:

1. C₃H₈+0₂ C0₂+H₂0
2. HCl+Na0H NaCl+H₂0
3. AgN0₃+NaCl AgCl+NaN0₃

 

BALANCE CHEMICAL EQUATIONS

aN₂+bH₂=cNH3

N: 2a  =C……(i)

H: 2b  =3C…..(ii)

Let a=1

From equation (i) 2 (1) = C

2 = C               C = 2

From equation (ii ) 2b =3 (2)

2b = 6

B =3

A =1,  b=3     C=2

N₂+3H₂=2NH₃

 

Two methods are commonly employed in chemical equations:

1. Balancing by inspection.
2. Balancing by the use of simultaneous equations.

 

See also

 

Air and Noise Pollution

Environmental Health

Classes of food

NUTRITION