Acid titration 1.1.2

• What does "volumetric analysis" refer to in the context of the study material?

  It is a process that uses the volume and concentration of one chemical to determine the concentration of another
• What is the first step in preparing a volumetric solution?

  Making a standard solution
• Why is it important to use precise equipment in volumetric analysis?

  To ensure accurate measurement of volumes
• How do you calculate the number of moles needed for a solution?

  By multiplying concentration by volume
• What is the difference between a concentrated solution and a dilute solution?

  A concentrated solution has a high concentration of solute, while a dilute solution has a low concentration
• What is the molar mass of sodium hydrogencarbonate (NaHCO₃)?

  84.0 g mol⁻¹
• How do you calculate the mass of sodium hydrogencarbonate needed for a specific concentration?

  By multiplying the number of moles by the molar mass
• What is the purpose of using a burette in titration?

  To accurately measure and deliver the volume of titrant
• What does the end point or equivalence point in a titration indicate?

  It indicates that the two solutions have reacted completely
• What should you do as you approach the end point of a titration?

  Slow down the flow of the burette and add the solution dropwise
• What are the steps involved in performing a titration?

  1. Measure a known volume of one solution with a volumetric pipette.
  2. Place it in a conical flask.
  3. Fill the burette with the other solution.
  4. Add a few drops of indicator to the conical flask.
  5. Open the burette tap to add the solution until the indicator changes color.
  6. Slow down the flow as you approach the end point.
• What are the key pieces of apparatus used in volumetric analysis?

  • Beaker
  • Burette
  • Volumetric Pipette
  • Conical Flask
  • Volumetric Flask
• What is the process of making a volumetric solution?

  1. Weigh the solute accurately.
  2. Dissolve it in a small volume of solvent.
  3. Transfer to a volumetric flask.
  4. Add solvent to the mark on the flask.
  5. Mix thoroughly.
• How do you determine the concentration of an unknown solution using titration?

  1. Perform a titration with a standard solution.
  2. Measure the volume of titrant used.
  3. Use the titration formula to calculate the concentration.
• What is the significance of concordant results in titration?

  • They indicate reliable and consistent measurements.
  • Typically, results should be within 0.1 cm³ of each other.
• What is placed under the conical flask during a titration to see the colour change more easily?

  A white tile
• What are the steps in a titration?

  1. Measure a known volume (20 or 25 cm³) of one solution with a volumetric pipette into a conical flask.
  2. Place the other solution in the burette, filled to 0.00 cm³.
  3. Add a few drops of indicator to the conical flask.
  4. Open the burette tap to add the solution dropwise until the indicator changes colour.
  5. Slow the flow as you approach the endpoint.
  6. Close the tap after one drop causes a colour change.
  7. Repeat until concordant results are obtained (within 0.1 cm³).
• What is the definition of concordant results in titration?

  Results that are within 0.1 cm³ of each other
• How should initial and final burette readings be recorded?

  With a precision of ±0.05 cm³
• What is the uncertainty for the volume delivered (titre) in a titration?

  ±0.10 cm³
• Why is the uncertainty doubled when calculating the titre?

  Because two burette readings are made
• How do you calculate the average titre from concurrent titrations?

  By averaging only those within 0.10 cm³ of each other
• What is the balanced chemical equation for the reaction between sodium hydrogencarbonate and hydrochloric acid?

  NaHCO₃ (aq) + HCl (aq) → NaCl (aq) + H₂O (l) + CO₂ (g)
• What was the concentration of the sodium hydrogencarbonate solution used in the titration example?

  0.200 mol dm⁻³
• How do you calculate the number of moles of sodium hydrogencarbonate used in the titration?

  Moles = concentration × volume
• What is the concentration of hydrochloric acid calculated in the example?

  0.182 mol dm⁻³
• How do you calculate the molar mass of an unknown monoprotic acid?

  By dividing the mass of the acid by the number of moles
• What is the average titre required for the neutralisation of the unknown monoprotic acid in the example?

  23.40 cm³
• What is the stoichiometric ratio between sodium hydroxide and the unknown monoprotic acid?

  1. 1
• How do you identify the halogen in the unknown monoprotic acid?

  By calculating the mass of the halogen and comparing it to periodic table values
• What is the mass of the halogen calculated from the unknown monoprotic acid?

  80.2 g
• Which halogen is identified based on the calculated mass of 80.2 g?

  Bromine (Br)
• What is the mass of the unknown monoprotic acid used in the titration example?

  0.133 g
• What is the molar mass of the unknown monoprotic acid calculated in the example?

  81.20 g mol⁻¹
• How do you calculate the number of moles of hydrochloric acid used in the titration of the unknown carbonate?

  By using the average titre and concentration of HCl
• What is the average titre for the hydrochloric acid titration in the carbonate example?

  14.95 cm³
• How do you calculate the number of moles of the unidentified Group 1 metal carbonate?

  By using the stoichiometric ratio from the reaction with HCl
• What is the molar mass of the unidentified Group 1 metal carbonate calculated in the example?

  106.132 g mol⁻¹
• How do you identify the Group 1 element in the unidentified metal carbonate?

  By calculating the mass of the element and comparing it to periodic table values
• What is the mass of the Group 1 element calculated from the unidentified carbonate?

  23.066 g