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2.;;(a) Lyman discovered a series of spectral lines for hydrogen in the ultra-violet region of the electromagnetic spectrum. What value must n1 have for this series? Give a reason for your answer.

(b);;;;;;Calculate the energy of a line in the Lyman series with ni = land n2 = 00.

(c) An experimental iodine laser emits light of wavelength 1.315gm. Calculate the frequency of this light and the energy per photon.

3.;;Predict the hybridization of the following:

(i);;;;;;PCl₅

(ii);;;SF₆

(iii);CO₂

(iv);BC1₃

(b);;;;;;Arrange the following substances in order of increasing melting points:;

C0₂, H₂0, CO, H₂;and Ar.

(c) Use VSEPR theory to predict the molecular geometry of the species PCL, NH₃;and PC1₅.

4.;;State two characteristics of compounds which are suitable for steam distillation.

(b);;;;;;An aromatic compound Z was steam distilled at 98.6⁰;C and 1 atmospheric pressure. The distillate was found to contain 25.5 grams of water and 7.4 grams of aromatic compound Z. Given that the saturated vapour pressure of water at 98.6⁰C is 720mmHg, calculate the relative molecular mass of the aromatic compound.

(c);;;;;;Benzene (C6H6) and toluene form a nearly ideal solution. At 313K the vapour pressure of pure benzene is 150mmHg and of pure toluene is 50mmHg. Calculate the vapour pressure of a mixture of these two liquids containing equal masses at the given temperature.

5.;;Define the following:

(i);;;;;;;Molar volume of a gas at s.t.p

(ii);;;;;;Dalton's law of partial pressure.

(b);;;;;;Two has burettes, one containing 10cm³;of sulphur dioxide (S02) and other containing 30cm³;of hydrogen sulphide (H₂S) both at I atmosphere and at O^OC are initially separated by a stop cork. The stop cork is then opened and the two gases are allowed to mix according to the reaction SO_2(g);+ 2H₂S_(S)→3S_(s);+ 2H₂0_(l)

Calculate the final pressure (in atmospheres) after the reaction has ended and the apparatus has regained its temperature of O^OC. (Assume liquid water does not exert pressure).

6.;;Distinguish between the following:

(i);;;;;;Reaction quotient and equilibrium constant.

(ii);;;;Chemical equilibrium and physical equilibrium.

;(b) (i) The Kc value for the reaction 2NO_(g);+ Cl₂;;;2NOCl_(g);is

4.6x 10⁴;dm³;moE^lat 298 Kelvin. Calculate the KP value for this equilibrium.

(ii) Calculate the KP value for the equilibrium 2NOC1_2(g);2NO +Cl_2(g);;at 298 Kelvin.

(c);;(i) For equilibrium reaction N₂(g) +3H₂(g);;2NH_3(g);derive KP and Kc relationship if the pressure of the mixture is P_T;and volume is V_T.

SECTION B

7.;;;(a) Three elements; F, G, and H have atomic numbers 17, 18 and 19 respectively.

(i);;;;Write electronic configuration of each element.

(ii);;;;;What type of ion each element is expected to form?

(iii);;;;In which group and period would each element be placed?

(b);;;;;Study the following hypothetical elements in a periodic table and then answer questions that follow.

Using letters indicated in the table, identify the following:

(i);;;;;The element which is the most electronegative.

(ii);;;;;A pair of elements that is likely to form the strongest electrovalent bond.

(iii);;;Two elements which are likely to have strongest reducing properties.;

(iv);;;Two elements which form neither negative nor positive ions.

8.;;(a) With reference to Modern periodic table, briefly explain the following

(i);;;;;Diagonal relationship.

(ii);;;;Anomalous behaviour

(b);;;;;Explain how the hydrides of period 3 elements react with water.

(c);;;;;;The following are;some oxides of elements Of;;period;;;;3:

Nap,;;A120₃, P₂0₅, Si0₂;and MgO. Arrange them in the order of

(i);;;;;;;Increasing in basic characters

(ii);;;;;Decreasing in ionic characters

9.;;(a) (i) What is the difference between the first and the second ionization energies of electron?

(ii) The first and the second ionization energies for the sodium atom are 493kJ and 4560kJ respectively. Account for such a big difference between the two ionization energies.

(b);;;;;By using chemical reactions, show how sodium reacts with the following:

(i);;;;;;;ethanol (ii) ammonia (iii) oxygen;;;;;;;;;;(vi) water

10.;;;;;;(a) State the law of mass action.

(b);;;;;One mole of PCI5 was introduced into a closed vessel ata certain temperature. By the time equilibrium was established, it was found that PC15 was 10% dissociated and the total pressure in the vessel was 4 atmospheres. Calculate:

(i);;;;;;;KP value at the temperature of the experiment

(ii);;;;;The total pressure at which PC15 was 20% dissociated.

11. (a) Complete the following equations for reactions of the alkanes:

;(b);;;;;;Write any three structural isomers of alkylicyclohexane of molecular formula C₆H₁₂.

(c);;;Write equations for the preparation of alkenes from the following starting materials, indicate the conditions required and if there is more than one product, indicate which one is major.

12.Write the Structure of the functional groups of the following sets of compounds:

1. Alkanes;;;;;;;;;;;;;;;;;;;;;;;;;;;; (ii) alkenes

;;;;;(iii) alkynes;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;(iv) alcohols

;;;;;(v) ketones;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;(vi) aldehydes

;;;;(vii) carboxylic acid;;;;;;;;;;;;;;;;;(viii)tertiary amines

(b) Give the IUPAC name of the following compounds

13.;;;;;With support of chemical reactions show how the following compounds can be prepared from ethanol as source of carbon atoms:;

(a);;;;;;;;Benzene

(b);;;;;;;Ethyl benzene

14.;;;;;(a) Write the structure of the major products for the reaction of gaseous hydrogen bromide with the following:

;(b);;;;;;;Explain how you can distinguish the following:

;