RP1-Standard solution and acid-base titration

• Solution equipment: weighing boat, mass balance, beaker, glass rod, volumetric flask, deionised water, acid salt
• Solution method: Weigh the acid salt by difference. Add deionised water and stir with a glass rod until fully dissolved. Transfer to a volumetric flask with washings and make up to the 250 cm^3 mark with deionised water. Add a stopper and invert several times.
• Titration equipment: Burette, standard acid solution, alkali solution, pipette and pipette filter, phenolphthalein, conical flask.
• Titration set up: Use a pipette to transfer exactly 25 cm^3 of unknown alkali solution into a conical flask and fill the burette with the standard acid solution. Add a few drops of phenolphthalein into the conical flask.
• Titration method: Complete a rough titre by releasing the contents of the burette until the alkali solution turns permanently pink. Then repeat with fresh alkali solution, adding dropwise when it is close to the endpoint. Repeat until two concordant results are obtained.
• Safety: Acids and alkalis are corrosive - if spilt immediately clean up, wear eye protection and a lab coat; acids are irritants even at low concentrations - wash hands thoroughly if spilt on them; may be using unknown substances - treat them as toxic.