Page 3 



12. a) Outline a simple process for making soap and explain the chemical 



reaction which takes place in its formation (without equation). 



b) Account for the action upon litmus paper of a solution of a soap which 



contains no free alkali. 



13. Five liters of carbon monoxide are mixed with just enough oxygen for com- 



plete combustion and the mixture is ignited. If the original gases are 

 measured at 20° C, at what temperature will the product occupy the same 

 volume, the pressure remaining the same ? 



14. State the reason for each of the following precautions: 



c) Potassium chlorate and manganese dioxide, for making oxygen, must not 



be ground too finely together. 



b) A hot object should be cooled before weighing. 



c) Concentrated solutions of acid and alkali should not be mixed without 



previous dilution. 



d) Phosphorus should not be handled with the fingers. 



15. a) Write equations illustrating three different methods for making sodium 



sulphate. 



b) Select any two of these equations and tell why the reaction goes to com- 

 pletion in each case. 



Is 



5(3 



