RP2 - Neutralisation

• What is the aim of the investigation described?

  To find the concentration of sulfuric acid
• What is the balanced chemical equation for the reaction?

  H​2​SO​4​ + 2NaOH ----> Na​2​SO​4​ + 2H​2​O
• What equipment is needed for the titration?

  • 25 cm​3​ volumetric pipette
  • Pipette filler
  • 50 cm​3​ burette
  • 250 cm​3​ conical flask
  • Small funnel
  • Clamp stand and clamp
  • White tile
  • 0.1 M sodium hydroxide solution
  • Sulfuric acid
  • Phenolphthalein indicator

  
• How much sodium hydroxide should be measured into the conical flask?

  25 cm​3​
• Why is the conical flask placed on a white tile?

  To better observe the color change
• What should be done before filling the burette with sulfuric acid?

  Record the initial reading of acid
• How should the burette readings be taken?

  From the bottom of the meniscus
• How many drops of phenolphthalein should be added to the conical flask?

  5 drops
• What happens to the solution near the endpoint of the titration?

  The color starts to change slightly
• What color change indicates the endpoint in phenolphthalein?

  From pink to colorless
• What should be recorded after the color change occurs?

  Final reading of acid in the burette
• What are concordant results in titration?

  Results within 0.1 cm​3​ of each other
• What should be done with the results after titration?

  Present results in a table
• How do you calculate the mean titre?

  By discarding anomalies
• How do you calculate the number of moles of sodium hydroxide used?

  By using the titre volume
• What is the ratio of sodium hydroxide to sulfuric acid in the reaction?

  2:1
• How do you find the moles of sulfuric acid?

  Divide moles of sodium hydroxide by 2
• What formula is used to calculate the concentration of sulfuric acid?

  Concentration = moles / volume
• What safety precautions should be taken when working with acids?

  • Wear safety goggles
  • Tie hair back
  • Report broken glassware