Chapter 1: Basic Concepts of Chemistry

Importance of Chemistry

• Chemistry is essential for understanding the substances we use.
• Helps in understanding significant figures, elements, mixtures, and chemical combinations.

Law of Chemical Combination

• Definition: Determines how elements combine to form compounds.
• Five Key Laws: Govern the combination process.

Law of Conservation of Mass

• Introduction: One of the fundamental laws in chemistry.
• Origin: Developed between the 1740s and 1780s.
• Concept:
  • Mass can neither be created nor destroyed.
  • The mass of reactants equals the mass of products.
• Example:
  • Reaction: Carbon + Oxygen → Carbon Dioxide.
  • Atomic Mass: Carbon = 12, Oxygen = 16.
  • Calculation: 12 (Carbon) + 32 (Oxygen) = 44, which equals the mass of Carbon Dioxide.
• Limitations:
  • Not applicable in reactions involving nuclear processes (E=MC²).

Example Problem

• Given: 1.5 grams of ethane combustion gives 44 grams of CO₂ and 2.7 grams of H₂O.
• Task: Prove that the reaction follows the law of conservation of mass.
• Action: Write the chemical equation and balance it to demonstrate mass conservation.