Balancing of Chemical Equations by Inspection and Algebraic Method

How to balance chemical equations by both Inspection and Algebraic Method

In life everything needs to be balance. Even in mathematics, that's why there is a slogan in maths what you do to the left hand side you do to the right hand side.

Now John Dalton Law of Conservation of Matter states matter(atom) can neither be created nor destroyed.

So we follow that rule in chemical equations, because if either side is greater than the other it means atom has being created or destroyed.
Things to Observe when balancing Chemical Equations.
1. You represent all elements and compounds with their formulas.
2. You don't tamper or alter the formulas given to you (i.e you don't change O2 to O3) the only thing you are permitted to do is to add moles to the elements or compounds until the equation is balanced.

Now let us solve some examples, before then i forgot to say there are two ways in balancing Chemical Equations namely:
1. By Inspection method
2. By algebraic method

Balancing of Chemical Equations by Inspection. 

1. Balance H2+O2 --> H2O
Now if you look carefully at the LHS hydrogen has a total of 2 and at the RHS hydrogen has a total of 2.
Oxygen at the LHS it has a total of 2 and at the RHS it has a total of 1.
Remember we can't add a subscript to chemical equations, so you can't say let me write (H2O2), so what will multiply the one(1) that oxygen has to give 2.
2×1=2, so add two to H2O. So now we have
H2+O2 --> 2H2O.
Now oxygen is balanced, but hydrogen is now 4 at RHS and 2 at LHS, so we add 2 to hydrogen at the LHS because 2×2=4,
2H2 + O2 --> 2H2O
The equation is balanced.
You can do an atom count to check.

2. C2H4 + O2 --> CO2 +H2O
Now carbon has 2 at LHS and 1 at RHS, so we add to 2, to make carbon at both sides balance.
C2H4 + O2 --> 2CO2 + H2O
hydrogen is 4 at LHS and 2 at RHS, so we add 2 to Hydrogen at RHS, to make hydrogen 4 at both sides.
C2H4 + O2 -->2CO2 +2H2O
Now oxygen has 2 at LHS and 6[{2×2=4 from 2CO2} +{2×1=2 from 2H2O}=4+2=6]
So what will multiply 2 that will give us 6,we all know it's 3,so add 3 to oxygen at LHS
C2H4 +3O2 --> 2CO2 + 2H2O
equation is balanced.

The rest examples are in the video below, don't forget to click the video below

Balancing of Chemical Equations by Algebraic method. 

1. Balance NH3+ O2--> NO + H2O.
Now in algebraic method, you represent your number of moles with letters. Then solve for the values of the letters then replace the letters with their values. So let us start.
so i will use letters x, y, z, and w in this case.
xNH3+ yO2 --> zNO + wH2O
Nitrogen
has 1 at LHS that will multiply x and one(1) at RHS that will multiply z, so lets equate this, we have
x=z
Hydrogen
3(x) = 2(w)
Oxygen
2y = z + w
Now we always our letter x to be 1. so x = 1,z=1,because x=z at our first equation.
3x=2w, we know the value for x but not for w so let us find the value for w.
3(1) = 2w
3=2w divide both sides by 2 to make w alone.
3/2 = 2w/2
w=3/2.
Our last equation
2y=z+w,substituting the values gotten for z and  w, we have 2y=1+3/2
2y = 5/2
dividing both sides by 2 we have y=5/2/2=5/2 ÷2
5/2×1/2=5/4.
Now substitute your values you gotten for the letters.
x=1,z=1,w=3/2, y= 5/4
1NH3+5/4O2 --> 1NO + 3/2H2O.
but moles are to be whole numbers and not fraction, so we multiply by the l.c.m of the denominator, i.e lcm of 2 and 4 which is 4,so multiply the whole equation by 4 we have
4NH3+5O2 --> 4NO +6H2O.

equation is balanced, there are more questions watch the video below to see more examples.

Drop a comment if you are confuse with what i just solved, you can also share my post with your friends.