Balanced equation :
C₂H₆+7O₂⇒4CO₂+6H₂O
<h3>Further explanation</h3>
Conservation of mass :
<em>In a closed / isolated system, the total mass of the substance before the reaction will be equal to the total mass of the reaction product.
</em>
Conservation of mass applies to a closed system, where the masses before and after the reaction are the same
This is the basis of reference, that the total atoms in the reactants will be equal to the total atoms in the product
The elements in the reaction will also be found in the product, but in the form of other compounds
Reaction

Let's look at the number of atoms in the reactants and products
C,left=2, right=1
H,left=6, right 2
O,left=2, right 3
So the equation not balanced
To balance, we can use the formula for burning alkanes or by using mathematical equations
1. Formula(in this case the hydrocarbon is ethane,n=2)

2. Mathematical equations
give equation
C₂H₆+aO₂⇒bCO₂+cH₂O
C,left=2, right=b⇒b=2
H,left=6,right=2c⇒2c=6⇒c=3
O,left=2a,right=2b+c⇒2a=2b+c⇒2a=2.2+3⇒2a=7⇒a=7/2
C₂H₆+7/2O₂⇒2CO₂+3H₂O x 2
C₂H₆+7O₂⇒4CO₂+6H₂O