Question

How to balance chemical equation???????

Answer 1

the both sides elements of equation should be equal...

Check that the valency of elements on both side is equal..
for example...
CO2 + H2O---> C6H12O6+O2
so in the above equation it is not balanced so... to balance it.. v need to balance so...
it would be 6CO2 +6 H2O---> C6H12O6+6O2

Answer 2

See all you have to do is to keep a check that no. Of atoms present on the left side(reactant side) of the arrow must be equal to the no. Of atoms in the right side(product side)

For example:

Mg+O2 ----> MgO (given equation)

Here no. Of 'O' atoms on the reactant side is 2
So we will add a '2' on the product side....
Now this forms the equation:
Mg+O2----> 2MgO

Here we can see our equation is still not balanced so we now put another '2' in front of Mg on the reactant side....

Hence we get a balanced equation :

2Mg+O2 ----> 2MgO

(The constants we put e.g. here '2' are in multiplication with the atoms)