In chemistry, we represent chemical reactions with chemical equations. The substances on the left-hand side of a chemical equation are the reactants, and the substances on the right-hand side are the products.
Chemical equations are balanced when the number of each type of atom on the left side of the equation is equal to the number on the right side.
The Correct Answer and Explanation is:
In chemistry, balancing chemical equations is essential to comply with the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. This means that the total number of atoms of each element must be the same on both sides of the equation: the reactants (left side) and the products (right side).
Chemical Equation Example:
For example, consider the reaction of hydrogen gas (H₂) with oxygen gas (O₂) to form water (H₂O):
Unbalanced Equation:
[ \text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O} ]
To balance this equation, we need to ensure the number of atoms for each element (hydrogen and oxygen) is the same on both sides.
Step-by-Step Balancing Process:
- Balance the hydrogen atoms:
- On the left side, hydrogen is present as H₂, meaning 2 hydrogen atoms per molecule. On the right side, H₂O has 2 hydrogen atoms per molecule.
- Since one molecule of H₂ produces one molecule of H₂O, hydrogen is already balanced.
- Balance the oxygen atoms:
- On the left side, O₂ represents 2 oxygen atoms per molecule.
- On the right side, each H₂O molecule contains only one oxygen atom.
- To balance the oxygen atoms, we need two H₂O molecules on the right side.
- Adjust the coefficients:
- The balanced equation is:
[ \text{2H}_2 + \text{O}_2 \rightarrow \text{2H}_2\text{O} ]
Now, both hydrogen and oxygen atoms are balanced. On the left side, we have 4 hydrogen atoms (from 2 H₂ molecules) and 2 oxygen atoms (from O₂). On the right side, we have 4 hydrogen atoms (from 2 H₂O molecules) and 2 oxygen atoms (from 2 H₂O molecules). Therefore, the equation is balanced.
Conclusion:
Balancing chemical equations is crucial in ensuring that the reaction follows the law of conservation of mass. This process helps in determining the exact amounts of substances involved in a chemical reaction, which is vital in fields like stoichiometry and reaction yield calculations.