Overview: In this tutorial, the fundamentals of balancing chemical
reactions are reviewed.
In chemistry it is very important to understand the relationship between reactants
and products in a reaction. Stoichiometry is exactly that. It is the
quantitative relation between the number of moles (and therefore mass) of various
products and reactants in a chemical reaction.
Chemical reactions must be balanced, or in other words, must have the same number
of various atoms in the products as in the reactants.
If a chemical reaction is not balanced, no information about the relationship
between products and reactants can be derived. So the first thing to do when
you see a chemical reaction is to balance it. We balance reactions by adding
coefficients in front of the reactants and products. These coefficients are the stoichiometric
Balance the chemical reaction.
This equation is not balanced since there are more N and O atoms on the left
side of the equation. Let's start by using the guidelines. Assign a stoichiometric
coefficient of 1 to the most complex compound, NO.
We can get rid of the fractional coefficients by multiplying by 2 even though
this is a perfectly acceptable balanced chemical equation.
At the very beginning of this problem, perhaps you could see this was the answer.
If you can see the balanced equation by sight, you don't need to go by the guidelines.
Remember they are only guidelines to help if you run into trouble. You can see
by simply adding a 2 in front of NO, we violate the first guideline even though
it leads us to a balanced equation.