Story of balancing chemical reactions
Answers
A chemical equation shows the chemical formulas of substances that are reacting and the substances that are produced. The number of atoms of the reactants and products need to be balanced. In this lesson, we will discuss balancing chemical equations.
Balancing Chemical Equations
Let's take a look at this scale. We can see that it is unbalanced, with the right (red) side, weighing more than the left (blue) side. In order for the two sides to be balanced, we need to put a little more mass on the left side until they are the same mass.
Just like we want the scale to be balanced on both sides, a chemical equation should also be balanced on both sides. A chemical equation shows us the substances involved in a chemical reaction - the substances that react (reactants) and the substances that are produced (products). In general, a chemical equation looks like this:
According to the law of conservation of mass, when a chemical reaction occurs, the mass of the products should be equal to the mass of the reactants. Therefore, the amount of the atoms in each element does not change in the chemical reaction. As a result, the chemical equation that shows the chemical reaction needs to be balanced. A balanced chemical equation occurs when the number of the atoms involved in the reactants side is equal to the number of atoms in the products side.
Let's take a look at an equation representing a chemical reaction:
In this chemical reaction, nitrogen (N2) reacts with hydrogen (H) to produce ammonia (NH3).The reactants are nitrogen and hydrogen, and the product is ammonia. If we look at this equation, we can see that the equation is not balanced.
The equation is not balanced because in the reactants side, there are 2 nitrogen (N) atoms and 2 hydrogen (H) atoms. In the products side, there are 1 nitrogen (N) atoms and 3 hydrogen (H) atoms. The number of the atoms is not balanced on both sides.
To balance the chemical equation above, we need to make use of coefficients. A coefficient is a number that we place in front of a chemical formula. In the chemical equation, to make the number of nitrogen (N) atoms equal on both sides, first, we place a coefficient of 2 in front of NH3.
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Once we do that, the number of nitrogen (N) atoms on both sides is balanced. However, the number of hydrogen (H) atoms is not balanced on both sides. We need to make use of another coefficient in front of H2. This time, we put a coefficient of 3 in front of H2 to balance the chemical equation.
The equation above is now balanced. There are 2 nitrogen (N) atoms and 6 hydrogen (H) atoms on both the reactants and products side. Since there is no coefficient in front of N2, that means the coefficient is equal to 1.