Chemistry (II)

• Law of conservation of mass

  "Atoms are neither created or destroyed during a chemical reaction, they only change the way they are arranged."
• Exothermic reaction

  A chemical reaction that gives off heat as it occurs
• Endothermic reaction

  A chemical reaction that absorbs heat as it occurs
• acid: A compound/molecule with sour taste, a pH below 7 and turns blue litmus paper red
• bases: A compound/molecule with bitter taste, a pH above 7 and turns red litmus paper blue
• common uses for acids:

  • aerated/soft drinks (Pepsi, Sprite, Cola, etc)
  • car batteries/paint
  • wine manufacturing
  • acid rain
• common use for bases:

  • soaps
  • detergents
  • baking soda
• pH scale:

  • measures how acidic or alkaline a solution is
  • determines pH of a solution (the lower pH, the stronger the acid)
• indicators: chemical dyes that change colours at certain pH levels