Required practical Chemistry C1 to C7

Making a copper salt

sulfuric acid + copper (III) oxide ----------> copper (III) sulfate + water

• Add insoluble copper oxide to hydrochloric acid and stir. Warm gently on a tripod and gauze. Do not boil
• The solution turns blue as the reaction happens showing copper sulfate being formed. Excess balck copper oxide can be seen
• When the reaction is complete, filter the solution to remove excess copper oxide 
• Evaporate the solution so that copper sulfate crystals are formed. Stop heating when the first crystals appear at the edge of the solution. Then leave for the rest of the water be evaporated. Excess water can be removed by dabbing crystals between fliter paper

You may be asked to design an experiment for an insoluble oxide and acid 

• Use a pipette and pipette filler to add a set volume of the alkali into a conical flask. Add two or three drops of indicator (methyl orange, litmus or phenolphthalein).
• Use a funnel to fill a burette with some acid of known concentration. Make sure this is done BELOW EYE LEVEL so acid does not spill on eyes. Record the initial volume in the burette. 
• Using the burette, add acid to the alkali a bit at a time, swirling the conical flask regularly. Go slowly when you believe the end point or colour change is about to occur. 
• The indicator changes colour when all the alkali has been neutralised. 
• Record the final volume of the acid in the buretter and with the initial volume reading, calculate the volume of acid needed to neutralise the alkali. 

Indicators

                                            COLOUR IN ACID                             COLOUR IN ALKALI

Phenolphthalein                     colourless                                        pink

Litmus                                  red                                                  blue

Methyl Orange                      red                                                  yellow

Precipitation Reactions

• A cross is drawn on a piece of paper
• A reactant is added to a conical flask and placed on the cross
• The other reactant is added and a stopwatch is started
• If the reactants are coloured and go colourless or vice versa, when this happens the stopwatch is stopped

'Change in mass' reactions

• One of the reactants are added to a conical flask and placed on a balance
• The other reactant is added and a stop watch is started
• A cotton ball is placed in the conical flask 
• As the gas is released, the mass disappearing is measured on the balance and recorded in regular time intervals

Volume of gas reactions: A gas syringe is placed above a reaction taking place and the volume of gas given off is measured in regular time intervals.