Practise laboratory apparatus, separation, titration, chromatography and qualitative tests across the CAIE IGCSE Chemistry experimental techniques unit.
Sulfur is an important element.
Dilute sulfuric acid is used to make salts known as sulfates.
A method consisting of three steps is used to make zinc sulfate from zinc carbonate.
step 1 Add an excess of zinc carbonate to of dilute sulfuric acid until the reaction is complete.
step 2 Filter the mixture.
step 3 Heat the filtrate until a saturated solution forms and then allow it to crystallise.
Name a suitable piece of apparatus for measuring of dilute sulfuric acid in step 1.
What is meant by the term saturated solution in step 3?
Dilute sulfuric acid and aqueous sodium hydroxide can be used to prepare sodium sulfate crystals using a method that involves titration.
Suggest why universal indicator is not suitable for this titration.
Name an indicator that can be used in this titration.
of dilute sulfuric acid neutralises of aqueous sodium hydroxide. At the end of the titration the conical flask contains aqueous sodium sulfate with the dissolved indicator as an impurity.
Sodium hydrogensulfate, , dissolves in water to produce an aqueous solution, X, containing and ions.
State the observations when the following tests are done.
A flame test is carried out on X.
Acidified aqueous barium nitrate is added to X.
Name the process used to:
separate an insoluble solid from a mixture of an insoluble solid and a solution
identify the components of a mixture of soluble coloured substances
separate a mixture of several liquids with different boiling points
determine the volume of an acid required to neutralise a given volume of an alkali.
The chemical equation for the complete combustion of ethanol, , is shown.
The energy released when one mole of ethanol undergoes complete combustion is 1280 kJ .
Part of the energy level diagram for this reaction is shown.
Dodecane is an alkane containing 12 carbon atoms. Ethanol can be manufactured from dodecane in a two-stage process.
In stage 1, each molecule of dodecane is converted into three molecules of ethene and one molecule of another hydrocarbon.
Suggest how to test the purity of the ethanol produced.
Ethanol can also be manufactured by the fermentation of glucose, .
Suggest the name of a process to obtain ethanol from a mixture of ethanol and water.