- The dissociation of water is an endothermic process. Explain why the value of Kw increases as the temperature increases. (2 marks)
- Predict with reason, the sign of the enthalpy change for the ionisation of water (1 mark)
- Write an equation for the reaction of aqueous propanoic acid with nitric acid(1 mark)
- Write an ionic equation for the reaction of aqeous propanoic acid with aqueous sodium carbonate (1 mark)
- Explain why [H2O] is not shown in the Kw equation (1 mark)
- Explain why water is neutral at 50 degrees (1 mark)
- Suggest why the pH probe is washed with distilled water between each of the calibration measures (1 marks)- 2021
- HALF EQUIVALENCE POINT
- explain why a burette is more suitable than a pipette to measure out sodium hydroxide solution (1 mark)
- State which is the stronger base, ammonia or ethylamine. Explain your answer. (3 marks)
- a pH meter is used to measure the pH of some hydrochloric acid. Describe how a pH meter is calibrated before use (2 marks)
- Give a reason why universal indicator is not a good choice for any titration (1 mark)
- Explain why there is no suitable indicator for the titration of a weak acid and weak base (1 mark)
- Suggest why chloroethanoic acid is a stronger acid than ethanoic acid (2 marks)
