Gen. Chem (Pre-final)

• Classification of System

  • Open systems - allow the transfer of mass and energy
  • Isolated systems - do not allow
  • Closed systems - allow the flow of energy but not mass
• STOICHIOMETRY

  • Explains that matter and energy are neither created nor destroyed one is being converted to another form of energy.
  • defined by the law of conservation of mass and energy
• How can the flow and conversion of energy be determined?

  Thermochemistry
• THERMOCHEMISTRY

  • branch of chemistry that studies the energy changes (usually in the form of heat) that accompany chemical reactions and physical transformations.
  • concerned with the relationships between chemical reactions and energy changes involving heat.
• What is the similarity between physics and chemistry?

  • conversion of energy
  • E=mc^2 or formulas are usually the same.
  • they both study matter.
• 2 Classification of energy:

  1. KINETIC ENERGY - Energy in motion
  2. POTENTIAL ENERGY - Energy at rest
• Other forms of energy:

  • Mechanical energy - result from physical work
  • Radiant or light energy - result from electro-magnetic wave
  • Electrical energy - comes from moving charge
  • Thermal or heat energy - comes from the constant motion of molecules
  • Chemical energy - which is stored within the structure or substances
  • Nuclear energy - comes from nuclear reactions
• Label the forms of energy

  A) Nuclear energy

  B) Light

  C) Electric energy

  D) Magnetic energy

  E) Potential energy

  F) Kinetic energy

  G) Chemical energy

  H) Thermal energy

  
• Energy is the capability to do work, thus, may also define as the process of expending energy.
• In chemistry, energy is the discussions of the flow of chemical reactions.
• Energy is not only utilized in physical activities but also in chemical reaction.
• Heat - is defined as the transfer of thermal energy if heat is being absorbed or released it means that there are two objects. involved the donor and receiver.
• • In chemistry the two objects are; system - particular area of interests sorroundings - everything outside the particular interests ( outside but within the box)
• Chemical reagents inside a test tube are considered as the system while that are outside the test tube are the surroundings.
• 2 types of transfer of Energy Endothermic process - transferring heat from the system to the surroundings. Exothermic process - If the flow of heat is from the surroundings to the system.