sample of essay question trial spm kedah 2010(sorry cannot insert the diagram)

by **fatin izzati>kurtdorisia** Sun Sep 19, 2010 5:01 am

The reaction takes place in the diagram is redox reaction (the diagram on salt bridge and the magnesium plate immersed in magnesium sulphate solution and copper plate immersed in copper (II) sulphate solution)

a) Explain the above statement. your explanation should include:
-the definition of redox reaction
-the half equations for the reactions at both terminals [6 marks]

b) diagram shows two type of cells.
{Cell P has a switch, voltmeter, zinc plate immersed in zinc sulphate solution and copper plate immersed in copper (II)
chloride solution in a porous pot}
{Cell Q has a dry cell and both anode and cathode is copper plate which is immersed in copper (II)
chloride solution}

Compare and contrast cell P and cell Q.Include in your answer
*the energy change in the cells
*the observations and half equations for the reactions at the electrodes in both cells [6 marks]

C) A student intends to electroplate an iron spoon with silver to prevent it from rusting.

Design a laboratory experiment to electroplate the iron spoon.

Your answer should consist of the following
*procedures of the experiment
*a labelled diagram showing the set up of apparatus
*the half equations for the reactions at both electrodes
*observation at both electrodes [8 marks]