2. Section A consists of THREE structured questions, one from each Module ..Section B consists of THREE extended response questions, one from eachModule.

3. For Section A, write your answers in the spaces provided in this booklet. ForSection B, write your answers in the answer booklet provided.

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In 1803, John Dalton came up with a series of postulates concerning the atom whichlater became known as Dalton's atomic theory.

(ii) Identify TWO of Dalton's postulates which were proven invalid by modematomic theory.

(b) A student was asked to investigate the relative reducing abilities of the elements zincand copper.

(i) List TWO chemicals and ONE piece of apparatus that the student may use tocarry out the investigation.

(iv) Write relevant half equations to illustrate the chemical changes that occur withEACH element.

(c) One type of kidney stones is formed by the precipitation of calcium phosphate(Ca/P04)2)' which has a Ksp of 1.3 x 10-32 at 25C. A patient submitted a urinesample which contained concentrations of 1.2 x 10-4 mol dm-3 calcium ions and1.1 x 10-8 mol dm-3 phosphate ions.

(i) Write a balanced equation for the formation of calcium and phosphate ions fromcalcium phosphate.

(d) Outline an experimental procedure for the determination of the solubility productconstant of barium hydroxide Ba(OH)20

Elements Mg Ca Sr Ba

Second lonisation 1450 1150 1060 970Energy (kJ mol-i)

Use the information in Table 1 to account for the differences in reactivity of the elementsshown.

(c) Radium, Ra, is the last member of the Group II elements. Using a knowledge ofGroup II chemistry,

(ii) write the balanced equation for the thermal decomposition of the nitrate ofradium, Ra(N03)2.

State the steps that should be taken in the investigation of the differences insolubility of the sulphates of magnesium, calcium and barium.

State the FOUR basic assumptions of the kinetic theory with reference to an idc:.l1 :1.I 4 ma.-!

Copy and complete the information in Table 2 regarding some physical properties ofelements in Group IV of the Periodic Table.

Element C (Diamond) Si Sn Pb

ElectricalSemi-conductor ConductorConductivity

Structure Giant molecular Giant metallic

(b) Both melting and boiling points of Group IV elements decrease from carbon to leadwhile there is an increase in their densities.

(ii) When exposed to the atmosphere, SiCl4 produces white fumes while no suchfumes are produced with CCI4. [ 3 marks]

(ii) state the name and the formula of the substance responsible for the presence ofthe white fumes. [ 2 marks]