Practical endorsement

• What laboratory equipment is used to measure reactant volume in titration?

  Pipette
• How does a burette function in a titration?

  It adds small volumes of reactant controlled
• What apparatus is used to heat a substance under reflux?

  Quickfit apparatus
• What happens to a substance in a pear-shaped flask during reflux?

  It evaporates, cools, and condenses back
• Why is heating under reflux beneficial?

  It prevents boiling dry and ensures even heating
• What is the purpose of a condenser in reflux?

  To cool and condense vapor back to liquid
• What is the process of distillation used for?

  To separate substances based on boiling points
• How does distillation work in a laboratory setting?

  Substance evaporates, cools, and condenses in a flask
• What equipment is used for filtering under reduced pressure?

  Buchner funnel and Buchner flask
• How does vacuum filtration work?

  Liquid is sucked through filter paper by vacuum
• What defines a standard solution?

  A solution of known concentration
• What is the first step in making a standard solution?

  Measure the mass of solid required
• What are concordant results in titration?

  Titres within 0.1 cm³ of each other
• Why are acid-base indicators used in titrations?

  To detect completion of the reaction by color change
• What is the process of recrystallization used for?

  To purify a solid product
• How do you purify a liquid product?

  Use a separating funnel and distillation
• How is the melting point of a substance determined?

  By melting a sample in a capillary tube
• Why is melting point information useful?

  To identify substances by comparing known values
• What is the purpose of thin layer chromatography?

  To separate mixtures for analysis
• How is an Rf value calculated?

  Rf = Distance travelled by component ÷ Distance travelled by solvent
• How is an electrochemical cell set up?

  Two half cells connected by a salt bridge
• What methods can measure the rate of reaction?

  Initial rates method and continuous monitoring
• What is the weighing by difference method?

  Weighing the mass before and after transfer
• Why might experimental enthalpy change values differ?

  Heat loss, incomplete combustion, non-standard conditions
• What is heating to constant mass?

  Repeated heating until mass stabilizes
• How is the volume of gas from a reaction measured?

  Using a gas syringe
• What are common laboratory hazards?

  Burns, chemical irritation, glass breakage
• How can pH be measured?

  Using pH charts, meters, or probes
• How can a substance be kept at a constant temperature?

  By using a water bath