Titration and calculations

• What is titration used for?

  To prepare salts from soluble reactants
• How can concentrations and volumes of reactants be determined?

  By performing titrations
• What is an acid?

  A corrosive substance with pH lower than 7
• What causes acidity in a solution?

  A high concentration of hydrogen ions
• What is an alkali?

  A base that is soluble in water
• What is a titration?

  A quantitative procedure for reacting solutions
• What apparatus is needed for a titration?

  Pipette, conical flask, and burette
• How do you measure a specific volume of alkali for titration?

  Use a pipette to measure 25 cm³
• What is the purpose of the indicator in a titration?

  To show the pH change with color
• What should you do when the end-point of a titration is reached?

  Stop adding acid when color changes
• What is the titre in a titration?

  The volume of acid or alkali added
• How do you calculate the titre from titration readings?

  Final volume minus initial volume
• What should you do with titration results that are too low?

  Ignore the low result and calculate mean
• What is the method for carrying out a titration?

  1. Measure 25 cm³ of alkali with pipette.
  2. Add indicator and place on white tile.
  3. Fill burette with acid and note starting volume.
  4. Slowly add acid to alkali, swirling to mix.
  5. Stop when color change indicates end-point.
  6. Note final volume and calculate titre.
• How do you determine the mean titre from multiple titrations?

  Average the titres of consistent results
• What is the significance of repeating titrations?

  To ensure accuracy and reliability of results
• What are the steps to record titration results?

  • Record end volume for each titration.
  • Record start volume for each titration.
  • Calculate titre for each titration.
  • Identify consistent results for averaging.
• What is titration used for in chemistry?

  To prepare salts from soluble reactants
• How can concentration and volumes of reactants be determined?

  Through titration calculations
• What is the definition of a solute?

  • The dissolved substance in a solution
• What is the definition of a solution?

  • Mixture formed by a solute dissolving in a solvent
• What is the equation linking concentration, amount of solute, and volume of solution?

  Concentration = amount ÷ volume
• How do you convert cm3 to dm3

  Divide by 1,000
• What is the concentration of 0.5 mol of solute in 250 cm3 of solution?

  2.0 mol/dm3
• How do you calculate the amount of solute in a solution?

  Amount = concentration × volume
• What is the amount of solute in 2 dm3 of a 0.1 mol/dm3 solution?

  0.2 mol
• How do you calculate the volume of a solution from amount and concentration?

  Volume = amount ÷ concentration
• What is the volume of a 2 mol/dm³ solution containing 0.5 mol of solute?

  0.25 dm³
• How can concentrations be expressed in different units?

  In grams per decimetre cubed (g/dm³)
• What is used to convert between different units of concentration?

  The relative formula mass (M_r)
• What is Avogadro's constant?

  • 6.0 × 10²³ particles
• What does the term "mole" refer to in chemistry?

  • Amount of substance containing Avogadro's number of particles