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Boyle's law states that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature; i.e., in equation form, pv = k, a constant. ...

- The most common apparatus used in volumetric determinations are the pipette,buret, measuring cylinder, volumetric and conical (titration) flask. - A common use for desiccators is to protect chemicals which are hygroscopic or which react with water from humidity.

The model of an atom put forward by Ernest Rutherford in 1911 on the basis of experiments on the scattering of alpha particles. The model consisted of a very dense positively charged nucleus, with electrons orbiting round the nucleus.

The atomic mass is written as superscript = proton number + neutron number - Atomic mass of Cu is 64 = 29 + 35 - Atomic mass of Zn is 65 = 30 + 35 Proton number is written as subscript

Its electronic configuration in ground state is 1s2 2s2 2p6 3s2 3p6 4s1 3d5.

The method of collecting a gas produced by a chemical reaction will depend on its solubility and its density.

Uses of electrolysis: Electrolysis is used in the extraction of metals from their ores. It is used for refining certain metals such as copper and zinc. Electrolysis is used for the manufacture of chlorine. Electrolysis is used for electroplating many things we use every day.

This periodic table shows the valences of element groups.

Kipp's apparatus is a laboratory apparatus specially designed for producing small amount of gases and is used to produce usually hydrogen sulfide.

(a) \(_2^4He\) has its outermost / Valence shell fully filled with electrons / has maximum number of electrons in its outermost shell / duplet thus more stable whereas \(_4^9Be\) has incomplete filled outermost / valence shell hence less stable. (b) (i) 1H - 2 electrons / zero 3Li - 2 electrons (ii) 1H - it accepts one electron / donates one electron 3Li - it loses an electron to have a duplet shell (c) - nearness to raw material / feed stock - nearness to markets - labour supply - transportation - availability of power supply - government policy - away from residential areas - storage facilities for raw materials - source of water supply - conducive climate (d) - saves money / the plant does not have to operate for long to produce - reduces energy / reaction proceeds at a much lower temperature - no undesirable products are formed / catalyst is specific in action (e) From the equation: 8 moles of Cl\(_2\) reacts with 1 mole turpentine 1 mole of Cl\(_2\) = 71 g 8 moles = 8 x 71 = 568 g \(\frac{21.3}{568}\)g will react with 21.3 x 136 = 5.1 g OR 8 moles of Cl\(_2\) reacts with 1 mole turpentine 8 moles of Cl\(_2\) = 8 x 71 = 568 g 21.3 g of Cl\(_2\) = \(\frac{136}{71 \times 8}\) x 21.3 = 5.1 g OR Mole of Cl\(_2\) = \(\frac{21.3}{71}\) = 0.3 mole 8 moles Cl\(_2\) \(\to\) 136 g C\(_{10}\)H\(_{16}\) 0.3 mole Cl\(_2 \) = \(\frac{136}{8}\) x 0.3 = 5.1 g (f) Cracking is the breaking down of long chain hydrocarbons into smaller molecules by the action of heat and / or in the presence of a catalyst. (g) - nuclear charge - atomic size - electron configuration (h) Carbohydrates are molecules / organic compounds consisting of carbon, hydrogen and oxygen atoms usually with hydrogen and oxygen atoms in the ratio of 2:1. (i) Sugar Starch - monosaccharides / low molar Mass - polysaccharides / high molar mass - single units of specific molecules - long chains of single sugar molecule/ subunits linked together - general formula C\(_x\)H\(_{2y}\)\(O_y\) - general formula (C\(_6\)H\(_{10}\)O\(_5\))n - crystalline - amorphous / non crystalline - soluble in water - insoluble in water (j) (i) H\(_2\)CO\(_{3(aq)}\) \(\to\) H\(^+\)\(_{(aq)}\) + HCO\(_{3(aq)}\)\(^{-}\) OR H\(_2\)CO\(_{3(aq)}\) \(\to\) 2H\(^{+}\)\(_{ (aq) }\) + CO\(_{3(aq)}^{2-}\) OR H\(_2\)CO\(_{3 (aq)}\) + H\(_2\)O\(_{(l)}\) \(\to\) H\(_3\)O\(^+\)\(_{(aq)}\) + HCO\(_{3 (aq)}^-\) H\(_2\)CO\(_{3 (aq)}\) + 2H\(_2\)O\(_{(l)}\) \(\to\) 2H\(_3\)O\(^+\)\(_{(aq)}\) + CO\(_{3 (aq)}^{2+}\) (ii) CH\(_3\)COOH\(_{(aq)}\) + H\(_2\)O\(_{(l)}\) \(\to\) CH\(_3\)COO\(^-_{(aq)}\) + \(H_3\)O\(^{+}\)\(_{(aq)}\) OR CH\(_3\)COOH\(_{(aq)}\) \(\to\) CH\(_3\)COO\(^-_{(aq)}\) + H\(^+_{(aq)}\)

(a) (i) - action of an acid upon an active metal / metals higher than hydrogen in the reactivity series - preparation by double decomposition (reaction between two soluble compounds to produce an insoluble compound) - by neutralization (reaction between acids & bases) - action of an acid on trioxocarbonate (IV) of a metal - direct combination of elements - action of dilute acid on an insoluble base Examples: (ii) - Addition of granulated zinc to a dilute solution of tetraoxosulphate (VI) acid. Zn(s) + H\(_2\)SO\(_{4(aq)}\) → ZnSO\(_{4(aq)}\) + H\(_{2(g)}\) - Pb(NO\(_3\))\(_{2(aq)}\) + H\(_2\)SO\(_{4(aq)}\) → PbSO\(_{4(s)}\) + 2HNO\(_{3(aq)}\) OR Pb(NO\(_3\))\(_{2(aq)}\) + N\(a_2\)SO\(_{4(aq)}\) → PbSO\(_{4(s)}\) + 2NaNO\(_{3(aq)}\) 2NaOH\(_{(aq)}\) + \(H_2\)SO\(_{4(aq)}\) → Na\(_2\)SO\(_{4(aq)}\) + 2H\(_2\)O\(_{(l)}\) ZnCO\(_{3(s)}\) + H\(_2\)SO\(_{4(aq)}\) → ZnSO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\) + CO\(_{2(g)}\) - CaCO\(_{3(s)}\) + 2HCl\(_{(aq)}\) → CaCl\(_{2(aq)}\) + H2O\(_{(l)}\) + CO\(_{2(g)}\) - 2Fe + 3Cl\(_2\) → 2FeCl\(_3\) Fe + S → FeS - 2HNO\(_3\) + CuO → Cu(NO\(_3\))\(_2\) + H\(_2\)O (iii) Uses of Na\(_2\)CO\(_3\) - used as a water softner - manufacture of glass/paper/rayon/soaps/detergents/NaOH/Borax - food processing aid - pH modifier - swimming pool chemical - electrolyte - analytical reagent / standardization of acids (b) Use pure copper as the cathode and impure copper as anode and then use a named soluble copper salt e.g. CuSO\(_4\) solution as the electrolyte impure copper dissolves /CuCu\(^{2+}\) + 2e\(^-\) and will be deposited at cathode / Cu\(^{2+}\) + 2e\(^-\) Cu Wash the cathode to obtain pure copper. (c) (i) Mass of NaCl deposited = 39.0 – 36.3 g = 2.7 g % NaCl deposited = 2.7 x \(\frac{100}{39.0}\) = 6.92 % or 7.0% Mass of AgNO\(_3\) deposited = 952.0 – 297.0 = 655 g % AgNO\(_3\) = \(\frac{655}{952}\) x 100 = 68.8 % Or 69% (ii) AgNO\(_3\) (Silver trioxonitrate (V)) will be more efficiently crystallized because it has a higher percentage deposited.

(a) (i) - All elements consist of atoms which are indivisible - Atoms can neither be created nor destroyed - The atoms of an element are all alike but differ from those / atoms of other elements - When atoms combine with other atoms they do so in simple ratios - All chemical changes result from the combination or separation of atoms (ii) If A and B form more than one compound, since the atoms are indivisible, combination will be in (simple) integral ratios, as mass of atom of each element is fixed. (b) (i) - soap - margarine - propan – 1,2,3 - triol / glycerine Alkaline hydrolysis gives soap / propan-1,2,3-triol (c) Atomic radii increases down the group and decreases across the period hence the size of Beryllium (Be) is about the same as the size of Aluminium (Al). The charge densities of Be\(^{2+}\) and Al\(^{3+}\) cause almost the same effect. OR Periodic properties increase / decrease from left to right and decrease / increase down the group in the periodic table. A diagonal relationship / similar properties exist between a pair of diagonally adjacent elements in the second and third periods of the periodic table as in the case of Be and Al. (d) I\(_2\) + 2Na\(_2\)S\(_2\)O\(_3\) → 2NaI + Na\(_2\)S\(_4\)O\(_6\)

(a) (i) When water does not easily form lather with soap / when water contains dissolved calcium and magnesium salts. Water that does not easily lather with soap / Water that contains dissolved calcium and magnesium salts (ii) Prepare soap solution Measure volume of sample water from a burette or pipette titrate with shaking to permanent lather. take titre value say x cm\(^3\) Measure same volume of boiled sample water and then titrate with shaking take titre value say y cm\(^3\) Find ratio; \(\frac{\text{permanent}}{\text{Total}}\) = \(\frac{y}{x}\) (iii) Waste of soap - produces scum during washing with soap - blockage of pipes - scales in boilers / furring of kettles - leads to wastage of fuel - not suitable for tanning / laundry / textile/ paper manufacturing industries (b) (i) NaNO\(_3\) or KNO\(_3\) conc H\(_2\)SO\(_4\) (ii) concentrated H\(_2\)SO\(_4\) heat (over a sand bath) all glass apparatus (iii) 2HNO\(_3\) + S → H\(_2\)SO\(_4\) + 2NO OR 6HNO\(_3\) + S → H\(_2\)SO\(_4\) + 6NO\(_2\) + 2H\(_2\)O II. no reaction / reaction prevented / metal passive oxide formed which coats metal (c) Zinc oxide Lead (II) oxide Aluminium oxide Tin(IV)oxide Aluminium hydroxide Tin (II) oxide Lead (IV) oxide Beryllium oxide

(a) (i) 2SO\(_2\) + O\(_2\) + 2H\(_2\)O \(\to\) 2H\(_2\)SO\(_4\) (ii) Use BaCl\(_2\) solution it gives white insoluble solid / precipitate to form bariumtetraoxosulphate (VI) OR Add a solution of bariumtrioxonitrate (V), a white precipitate of bariumtetraoxosulphate (VI) is formed (iii) I. C\(_2\)H\(_2\)O\(_4\) \(\frac{-H_2O}{H_2SO_4}\) CO + CO\(_2\) (iv) I. H\(_2\)SO\(_4\) is acting as a dehydrating agent II. Cu + 2H\(_2\)SO\(_4\) → SO\(_2\) + CuSO\(_4\) + 2H\(_2\)O II. H\(_2\)SO\(_4\) is acting as an oxidizing agent (b) (i) Water is referred to as a universal solvent because it is able to dissolve more substances than any other liquid. This has to do with the polarity of each water molecule. The hydrogen side of each water molecule carries a slight positive electric charge, while the oxygen side carries a slight negative electric charge and this helps water dissociate ionic compounds into their positive and negative ions. (ii) Water will turn cobalt (II) chloride paper from blue to pink / anhydrous copper (II) tetraoxosulphate (VI) crystals from white to blue (c) (i) CO / Carbon (II) Oxide (ii) Because it is combustible / can be used as fuel (d) (i) coke (ii) coal tar / ammoniacal liquor / pitch (iii) coal gas (e) (i) C(s) + O\(_{2(g)}\) →CO\(_{2(g)}\) (ii) I. - It is odourless - It is colourless - It is denser than air - It is soluble in water - It is a gas at room temperature - It is easily compressible (ii) It does not support combustion It reacts with red hot carbon (to form CO) it is weakly acidic in water it reacts with alkali (to form trioxocarbonate (IV) ) / turns lime water milky Reacts with burning magnesium

(a) - high temperatures / stated temperature of 500\(^o\)C or more - catalyst (b) - To prevent corrosion/rusting/tarnishing - To make them shiny/for decoration purpose/beautify/attractive - To make surface harder/thicker - To make more resistant to chemicals - To make it durable - To reduce friction/abrasion (c) (i) Because calcium oxide is basic and hydrogen chloride is acidic ,they will react to form salt and water. (ii) - Fused CaCl\(_2\) - (Conc) H\(_2\)SO\(_4\) (do not accept dil H\(_2\)SO\(_4\)) - Silica gel - Phosphorus(V) oxide/P\(_2\)O\(_5\) (d) Conc. HNO\(_3\) is a strong oxidizing agent. It oxidizes pale green Fe\(^{2+}\) ions to yellow Fe\(^{3+}\) ions (1) and itself reduced to nitrogen (IV) oxide. (e) (i) I. ZnO(s) + H\(_2\)SO\(_{4(aq)}\) \(\to\) ZnSO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\) II. ZnO\(_{(s)}\) + 2NaOH\(_{(aq)}\) \(\to\) N\(a_2\) Zn(OH)\(_{4 (aq)}\) OR ZnO + 2NaOH \(\to\) Na\(_2\)ZnO\(_2\) + H\(_2\)O (ii) Amphoterism / Amphoteric properties (f) (i) Same number (17) of protons / same number (17) of electrons/same atomic number (ii) Difference in mass numbers / different number of neutrons / 35Cl has 18 neutrons and 37Cl has 20 neutrons (g) - HCl / hydrochloric acid - O\(_2\) / Oxygen (h) (i) H\(_2\)S (ii) SO\(_2\) (i) It is the mass reference scale in which the atom of the 12C isotope is taken to have twelve units of atomic mass OR It is a scale that uses the 12C isotope as the standard for comparing the atomic masses of other elements. (j) - The rate of forward reaction equals the rate of backward reaction / The system is dynamic - There is no net change in the concentration of each substance - The equilibrium compositions of the substances can be approached from either reactants or products - Gibb’s free energy/ is zero