Understanding Conservation of Mass in Chemical Equations

Conservation of mass is an important idea when we balance chemical equations.

It says that matter can't be created or destroyed during a chemical reaction.

This means that the total mass of what you start with (reactants) has to be the same as the total mass of what you end up with (products).

Let's look at an example:

Think about burning propane, which we can write like this:

$\text{C}_3\text{H}_8 + 5 \text{O}_2 \rightarrow 3 \text{CO}_2 + 4 \text{H}_2\text{O}$

1. Reactants (what you start with):

   • Propane ($\text{C}_3\text{H}_8$): It has 3 carbon atoms and 8 hydrogen atoms.
   • Oxygen ($\text{O}_2$): This has 5 oxygen atoms.

2. Products (what you end up with):

   • Carbon dioxide ($\text{CO}_2$): This has 3 carbon atoms and 6 oxygen atoms.
   • Water ($\text{H}_2\text{O}$): This has 4 hydrogen atoms and 4 oxygen atoms.

Now, if we count the number of each type of atom on both sides, we'll see that they match.

This shows that we have conserved mass.

Making sure everything balances helps us understand how chemical reactions work.