Aqa A Level Chemistry - Paper 3 Experiments Questions And Answers 100% Verified A+ Guaranteed

Distillation {Ans: NB, oxidation: Dilute acid and less K2Cr2O7 than needed. 1. Heat liquid to boil and vaporise the most volatile component in the mixture. Anti-bumping granules are used. 2. The vapour passes up from the flask and down into the condenser, where it is cooled by cold water and ice, and condenses back to a liquid (the distillate) which is collected in the flask. 3. Any dissolved solids are left in solution because they have too high a boiling point to be distilled over .}Measuring Enthalpy Change of Neutralisation {Ans: 1. Place polystyrene cup in glass beaker 2. Measure out 25cm³ of 1moldm³ HCl and transfer to polystyrene cup 3. Stir and record temperature 4. Measure out 25cm³ of 1moldm³ NaOH into another measuring cylinder. 5. Add NaOH to HCl, stir and record the highest temperature reached 6. Calculate temperature change and q=mcAT 7. Calculate moles of acid used and water formed, and the enthalpy of neutralisation}Thin Layer Chromatography {Ans: 1. Draw pencil line 1.5cm from bottom of TLC plate + place 2 pencil crosses on the line 2. Place a drop of the purified solid on a watch glass + dissolve in a few drops