8th Grade Home



Activity 5
Neutralization (Acid-Base) Reactions
NaHCO3 + CH3COOH  ---> Na2C2H3O2  + CO2  + H2O
sodium bicarbonate + acetic acid ---> sodium acetate + carbond dioxide + water

       

Materials needed for each station:
  • 1 test tube rack
  • 2 pipets (droppers)
  • 2 medium test tubes
  • 1 test tube stopper
  • 0.2 g sodium bicarbonate (baking soda)
  • 1 scoopula / spoon
  • 4 mL acetic acid (vinegar)
  • 4 mL water
  • 5 strips of wide range pH paper
  • 1 thermometer

Procedures:
  1. Use a scoopula to measure 0.2 g of sodium bicarbonate.  Place the sodium bicarbonate in a test tube with approximately 4 mL of water.  Securely close the test tube with a stopper and gently shake the tube until the sodium bicarbonate has completely dissolved in the water.  Label this tube as a "basic solution".  Place the tube in the rack.
  2. Pipet approximately 4 mL of vinegar into a second test tube.  Label this tube as acetic acid solution.  Place the tube in the rack.
  3. Measure and record the temperature of the contents of each tube.  Record your measurements into your lab book.
  4. Using a pH strip, record the pH of each solution into your lab book.
  5. Add drops of acid to the base, testing with pH paper, until the solution is no longer acidic or basic.  In other words, until the solution is neutral with a pH around 7.  Record the number of drops needed and the final pH you measured into your lab book.
  6. Immediately after neutralizing the solution, record the temperature of the mixture into your lab book.
  7. Answer the Results Questions for Activity 5.