Balancing Chemical Reactions

In this lesson, we will learn how to balance chemical reactions, ensuring that the law of conservation of mass is obeyed. A balanced chemical equation has the same number of each type of atom on both sides of the equation.

Steps to Balance a Chemical Equation

1. Write the unbalanced equation.
2. Count the number of atoms of each element on both sides.
3. Use coefficients to balance the atoms one element at a time, adjusting as necessary.
4. Check your work to ensure that all elements are balanced.

Example: Balancing the Reaction of Hydrogen and Oxygen to Form Water

1. Unbalanced equation: $H_{2} + O_{2} \rightarrow H_{2}O$

2. Count atoms:

   • Left: $2 H, \ 2 O$
   • Right: $2 H, \ 1 O$

3. Balance O by adding a coefficient of 2 in front of $H_{2}O$: $H_{2} + O_{2} \rightarrow 2H_{2}O$

4. Count atoms again:

   • Left: $2 H, \ 2 O$
   • Right: $4 H, \ 2 O$

5. Balance H by adding a coefficient of 2 in front of $H_{2}$: $2H_{2} + O_{2} \rightarrow 2H_{2}O$

6. Final check:

   • Left: $4 H, \ 2 O$
   • Right: $4 H, \ 2 O$

The equation is now balanced!

Key Questions

• What is the law of conservation of mass?
• Why is it important to balance chemical equations?
• How do coefficients differ from subscripts in a chemical equation?

Keywords

• Balancing
• Coefficients
• Conservation of mass
• Reactants
• Products