How do you balance the equation for the synthesis of aspirin?

To balance the equation for the synthesis of aspirin, we start with the unbalanced equation:

C₄H₆O₃ + C₇H₆O₃ → C₉H₈O₄ + C₂H₄O₂

Next, we count the number of atoms of each element on both sides of the equation:

• Left side:
• C: 4 + 7 = 11
• H: 6 + 6 = 12
• O: 3 + 3 = 6
• Right side:
• C: 9 + 2 = 11
• H: 8 + 4 = 12
• O: 4 + 2 = 6

Both sides have the same number of carbon, hydrogen, and oxygen atoms, which means the equation is balanced as it is. Therefore, the balanced equation for the synthesis of aspirin is:

C₄H₆O₃ + C₇H₆O₃ → C₉H₈O₄ + C₂H₄O₂

This equation shows how two reactants combine to form aspirin (C₉H₈O₄) and acetic acid (C₂H₄O₂). The conservation of mass principle states that matter cannot be created or destroyed in a chemical reaction, so it is crucial for a balanced equation to reflect that principle.