Topic 4 Vocab

• enthalpy 


  measure of the stored chemical potential energy in a substance
• heat of reaction 


  measure of change in enthalpy for a reaction and has both a magnitude and a sign
• heat of reaction formula 


  △H = H(products) - H(reactants)

  if negative then is exothermic

  if positive then is endothermic
• Law of Conservation of Energy 


  energy is neither created nor destroyed during a chemical reaction
• exothermic 


  a reaction in which the total enthalpy of products is less then the total enthalpy of reactants

  H(products) < H(reactants)
• endothermic 


  reaction total enthalpy of products is greater than the total enthalpy of reactants

  H(product) > H(reactants)
• rate of reaction 


  speed with which the reactants are converted intoproducts
• catalyst 


  substance that speeds up a chemical reaction but is not consumed in the reaction
• activation energy (Ea) 


  minimum energy required for a collision to occur
• transition state (activated complex) 


  energy required to form highest energy state in rearrangement of atoms and bonds
• absorption spectrum 


  spectrum of electromagnetic radiation transmitted through a substance, showing dark lines or bands due to absorption at specific wavelengths
• atomic absorption spectroscopy 


  analytical process used to determine concentration of metal ions in solutions