as level practicals

making up a volumetric solution

• weight out the solid onto a weighing boat

• add the solid to a beaker

• reweigh the weighing boat and record the difference in mass

• add 100cm³ of distilled water to the beaker (use some to wash out the weighing boat) and use a stirring rod to help to dissolve some of the solid

• pour into a 250cm³ volumetric flask

• rinse beaker and funnel and add washings to a volumetric flask

• make up to the line with the meniscus at the bottom of line using a dropping pipette for the last few drops

• invert several times to ensure a uniform solution

carrying out an acid base titration

• rinse the equipment (burette with acid, pipette with alkali, conical flask with water)

• pipette 25cm² of alkali into conical flask

• touch surface of alkali with pipette

• make sure the jet space in the burette is filled with water

• add a few drops of indicator to the alkali

• add a white tile underneath the flask to help observe the colour change

• add acid to the alkali while swirling the mixture and add the acid drop by drop at the end

• note burette reading before and after adding the acid

• repeat titration until at least 2 concordant results are obtained

measuring enthalpy change of reaction (solution)

• wash equipment with solutions to be used

• dry cup after wash

• put polystyrene cup in beaker

• measure out desired volumes of solutions with volumetric pipettes and transfer to insulated cups

• clamp thermometer in place

• record initial temperature of solutions

• add second reagent to cup

• stir mixture

• record temperature every minute for several minutes

• draw a cooling curve

purifying an organic liquid

• pour the distillate of an impure product into a separating funnel

• add sodium hydrogencarbonate solution, shake, release the pressure from the build up of CO2 to neutralise remaining acid

• add saturated sodium chloride to see organic layer

• allow the layers to separate then discard organic layer using separating funnel

• run the organic layer into a clean, dry conical flask and add drying agent (anhydrous sodium sulphate) to dry the organic liquid)

• carefully decant the liquid into the distillation flask

• distil to collect pure product

distillation

• pour alcohol into round bottomed flask

• set up quick fit apparatus

• heat with electric heater

reflux

• anti bumping granuals can be added to prevent uneven boiling my making sure small bubbles form

• reaction mixture placed in round bottomed flask

• flask is connected to condenser which is cooled by a constant water stream

• reaction mixture is heater and vapours condense