Unit 6 - Chemical Equations and Reactions

• Physical Changes


  alters a substance without changing its composites
• bend, dissolve, cut, break, etc. physical or chemical?

  physical
• are physical change reversable?

  yes
• Chemical Changes


  the change of 1 substance into another substance through a reorganization of the atoms
• react, burn, decay, etc. physical or chemical?

  chemical
• are chemical changes reversable?

  no
• Signs of chemical changes

  • change in color
  • odor
  • gas/vapor
  • heat, temp, energy
  • precipitate
• Law of Conservation of Mass/Matter


  in any physical or chemical process, mass/matter can't be created nor destroyed, only transferred.
• formula for equations

  reactants->products
• Synthesis


  2+ elements or compounds combine to form a large molecule as a product
• decomposition


  a complex molecule breaks down to make 2+ elements/compounds
• Single Replacement


  1 individual element trades places with another element in a different compound. metals always replace metals. non metals always replace non metals.
• Double Replacement


  when the anions and cations of two different ionic compounds switch places, forming two entirely different ionic compounds
• Neutralization(acid base)


  a double replacement reaction that happens when an acid and a base react with each other. H ion in acid and OH ion in base react causing the formation of water.
• acids begin with H
• bases end in OH
• combustion


  organic compound made up of C, H and maybe O, burns in the presence of oxygen to form water vapor and carbon dioxide. This reaction is exothermic and produces heat.
• solubility rule 1


  Group 1 elements are soluble
• solubility rule 2


  Compounds with NH4+ (ammonium) and NO3(nitrate) are always soluble
• solubility rule 3

  Ionic halogens, Chloride(Cl), bromide(B) and iodine(I), etc ions are soluble unless paired with silver(Ag), lead(Pb) and mercury(Hg)
• soluble = aqueous
• insoluble = solid