Have you ever wondered why balancing chemical equations is such an important practice in the field? Why is it necessary to go through such a turmoil for aspiring chemists as balancing of equations by putting those weird numbers before the reagents? You might find the answer rather beautiful.
Please make sure you understand how to calculate molecular (molar) mass of a molecule prior to proceeding below.
The main reason for balancing is to keep adhering to the law of mass and/or energy conservation which states: “Matter and energy can not appear out of nothing and disappear without a trace, they can only change the state in which they exist”. This is a rather fundamental statement which has some pretty important practical implications.
Another reason is that chemical equations are used for quantitative predictions of chemical reactions outcomes (i.e. to predict the amount of reactants and/or products of a certain reaction). And only a complete and balanced chemical equation is a correct model that depicts a certain chemical process and relation between reactants and products thereof. This chemical balance definition shows the importance of bringing an order to the equation.
How to know when your chemical equation is balanced
In order to make things more clear, we need to understand that each and every chemical equation consists of left part and right part, which are separated by “=” or “?“ (arrow of a pretty much any kind).
And now, let’s take a look at the couple of different chemical reactions. First, lets examine formation of Calcium sulfide.
The nature of this chemical process is such that two simple substances are reacting with each other, and every molecule of every reagent is considered to be consisting of just one respective atom. Therefore: one Calcium molecule (that consists of a single atom) reacts with one Sulphur molecule (that also consists of just one atom) and this reaction results in a single molecule that consists of each respective atoms. So we could write the first reaction like this, and that would be a great example of balancing equations in chemistry.
But in that way the things would look overly complicated, so in chemistry (pretty much like in math) we do not write “1” when a single molecule or single atom is assumed. A chemical equation is balanced when the amount of respective atoms before a reaction (left part of the equation) and after the reaction (right part) matches. So in our case, on the left we have one Calcium molecule with just one atom and a single Sulfur molecule with a lonely Sulfur atom. And on the right we have a single molecule with one Calcium atom and one Sulfur atom.
That is it! The numbers of respective atoms in both parts of equation is matching, the principle of mass/energy conservation is observed: the amount of matter and energy on the left part (before chemical process) equals to the amount of matter and energy on the right (after the chemical process). Therefore no further efforts are needed.
Now let’s take a look on the formation of water by burning Hydrogen:
This is the example of unbalanced chemical equation. Why? If we look at the equation above, the number of atoms of respective elements is not equal on the left and right parts of it. We have two Hydrogen atoms in the first molecule and two Oxygen atoms in a second molecule and this produces a single molecule of water that has two Hydrogen and one Oxygen atoms. While the number of Hydrogen on the left and right parts of equation is matching, we have a missing oxygen atom on the right. And this is not possible that an atom is lost in a chemical process. Balancing is needed here in order to figure out how all the compounds of this reaction are connected.
Now let’s complete the balancing. The correct and balanced reaction is shown below:
We have two Hydrogen atoms in two molecules (therefore 4 atoms of Hydrogen in total) and two Oxygen atoms in a single molecule on the left. The reaction yields one two water molecules that have 2 hydrogen atoms and one oxygen atom each. Therefore the number of respective atoms is matching on the left and right parts of equation, the principle of mass conservation is complete.
A very important implication of this balanced equation is that per each two certain amounts of water molecules produced, we need two same amounts of hydrogen molecules and one amount of oxygen molecules.
That is it. You know the beauty of chemical reactions now: it is indeed all about the balance between reactants and reaction products. Go to our chemical reactions database and find your perfectly balanced equations and proceed with solving problems using our innovative service. Still have any questions or got any comments? Go ahead and write them below!
Everything comes with practice, so please, make sure you run through balancing a dozen of reactions and nail it!
That is it. You know the beauty of chemical reactions now: it is indeed all about the balance between reactants and reaction products. Go to our chemical reactions database and find your perfectly balanced equations and proceed with solving problems using our innovative service. Still have any questions or got any comments? Go ahead and write them below!
Please, support this service on Patreon, visitors like you make the existence of this website possible.
no replies