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The difference between every successive member of the same homologous series is always \(CH_{2}\) eg methane is \(CH_{4}\) and ethane is \(C_{2}H_{6}\), difference being \(CH_{2}\).

\(Cu^{2+} + 2e^{-} \to Cu_{(s)}\) \( 2 \times 96500C = 193000C deposits 64g of Cu\) \(M \propto It\) \(Q = It = 0.45A \times 1hr15mins\) = \( 0.45 \times 75 \times 60\) [converting the time to seconds] Quantity of electricity passed = 2025C \(193000C \to 64g Cu\) \(1C \to \frac{64}{193000}\) \(2025C \to \frac{64}{193000} \times 2025\) \(= 0.6715g \approxeq 0.67g\)

Alkanols can be classified as primary, secondary or tertiary, according to the number of alkyl groups attached to the carbon which bears the -OH group.

The alkyl group is attached to the parent chain being a carboxylic acid. The name of the compound is gotten by writing the name of the attached alkyl group first and then the parent carboxylic acid is written but you change the -oic acid to -oate. The alkyl group in this case is \(C_{3}H_{7}\) The parent carboxylic acid is \(C_{4}H_{9}COOH\) which is pentanoic acid. Hence, the name is propyl pentanoate.

No expanded working has been attached for this question yet. The verified answer is Option C.

Paraffin oil is gotten from petroleum distillation and can't be a source of fats and oil.

A maltose is a dissacharide formed from two units of glucose.

The parent chain for the compound is \(C_{2}H_{5}OH\) in which one of the hydrogen atoms is replaced by the Cl atom. Giving the chlorine the highest number while naming, we have 2- chloroethanol.

Chlorofluorocarbons are harmful to environment and living beings because it increases greenhouse gases in the environment which results in forming holes in the ozone layer.. And if this happens it will cause to an increase in the ultraviolet rays exposer, and which will make the earth's surface much hotter than usual.

Alkanols have the formula \(C_{n}H_{2n+1}OH\). ⇒ \( 12n + (1\times (2n+1)) + 16.0 + 1.0 = 60\) = (14n +18 = 60\) \(n = \frac{60-18}{14} = \frac{42}{14} = 3\) Hence, the alkanol is gotten by putting n=3, =\(C_{3}H_{7}OH\)

No expanded working has been attached for this question yet. The verified answer is Option D.

a)(i) An acid-base indicator is either a weak organic acid or base which gives different colours in an acidic or basic mediurn. (Organic dye which changes colour according to the pH/hydrogen ion concentration of the solution). (ii) Example of an acid-base indicator is: (i) phenolphthalein. (ii) methyl red. (iii) methyl orange. (iv) methyl yellow (v) alizarin yellow. (vi) litmus paper/solution. (vii) methyl violet. (viii) bromothymol blue (ix) bromocresol green. (b) Property exhibited by nitrogen (IV) oxide in each of the following equations: (i) 4Cu + 2NO\(_2\) —> 4CuO + N\(_2\), NO\(_2\) is an oxidizing agent (ii) H\(_2\)O + 2NO\(_2\) —> HNO\(_3\) + HNO\(_3\), NO\(_2\) is oxidizing agent as well as a reducing agents or NO\(_2\) serves as acid anhydride or mixed anhydride. (c)(i) Enthalpy of combustion is the amount of heat evolved or liberated when one mole of a substance is burnt mpletely in excess oxygen. (ii) Enthalpy of combustion is always negative because heat is always given out or the action is exothermic. (d) To distinguish between primary cell and secondary cell. (i) (a) Primary cells cannot be recharged while secondary cells can be recharged. (b) Primary cells do not last long while secondary cells last long. (c) Reactions in primary cells are not reversible while reactions in secondary cells are reversible. (ii) Examples of each of the cells in 1(d)(i). Primary cell: radio battery, dry cell, alkaline battery, button battery, Le'clanche cells, Daniel cell, torch battery, clock battery, bicycle lamp battery (any of these). Secondary cell: lead-acid (storage - cell), lead-acid accumulator, lithium-ion battery, battery in rechargeable lamp, car battery, nickel-metal hydride cell, phone battery, nickel-cadmium cell, (hydrogen-oxygen) fuel cell, aluminium air cell/battery (any of these). (e) Mole is defined as the amount of substance containing 6.02 x10\(^{23}\) particles of that substance as present in 12g of carbon-12 or the amount of substance containing as many elementary entities as there are atoms in 12g of carbon-12. (f) Amount of hydrochloric acid in 40.0cm\(^{3}\) of 0.40 mo/dm\(^{3}\) dilute HCl n = CV; C = concn in mo/dm\(^{3}\) n = 0.40 x \(\frac{40}{1000}\); V = volume in dm\(^{3}\) n(mol) = 0.016mol; n = amount in mol (g) Two substances used as electrodes during electrolysis of acidified water are: graphite (carbon) and platinum. (h) Two forces of attraction that can exist between covalent molecules (1) Van der waals' forces or induced dipole-dipole forces. (2) Hydrogen bonds. (3) Permanent dipole-dipole interactions or dipolar forces (any of the two): (i) Products formed when butane undergoes incomplete combustion are carbon (ii) oxide and water. (j) Electron configuration of \(_{26}\)Fe\(^{3+}\) \(_{26}\)Fe; Fe - 3\(\bar{e}\) \(\to\) Fe\(^{3+}\) lost of 3 electrons \(_{26}\)Fe 26 protons + 26 electrons \(_{26}\)Fe\(^{3+}\) 26 protons + 23 electrons \(_{26}\)Fe\(^{3+}\) \(\to\) 1s\(^2\), 2s\(^2\), 2p\(^6\), 3s\(^2\), 3P\(^2\), 3d\(^5\)

(a)(i) The periodic law states that the properties of the elements are a periodic function of their atomic numbers. (ii) Periodic property of element(s) is any physical or chemical property of an element which changes regularly with increasing atomic number. (ii) Three properties of an element which show periodicity are: melting/boiling point, ionization energy, electron affinity, electronegativity/electropositivity, atomic/ionic radius, eletrical and thermal - conductivities/metallic and non metallic properties. (iii) Brief explanation of properties of an element which shows periodicity across the period: (1) Melting/boiling points of metallic elements increase due to increase in strength of the metallic bond while melting/boiling point for non-metallic elements decreases due to decrease in Van der waals' forces of attraction. (2) lonizatioin-energy increases due to increase in proton number or increase nuclear charge or decreased atomic radius. (3) Eleetron affinity increases due to decrease of atomic radius or increase in nuclear charge. (4) Eleclronegativity of elements increases due to increased nuclear charged or decreased atomic radius. (5) Electropositivity of elements decreases due to increased nuclear charge (6) Atomic/ionic radius decreases due to increased nuclear charge or increase in proton number or increase in effective nuclear charge. (7) Metallic character (electrical/thermal) decreases because of increase in covalent character (b) Relative atomic mass defined as the number of times the average mass of one atom of an element is heavier than one twelfth the mass of one atom of carbon-l2. OR the ratio of the average mass of one atom of an element to one twelfth the mass of an atom of carbon-12 OR the average mass of one atom of an element on a scale in which one atom of carbon 12 weighs 12 a.m.u. (c) (i) Phenomenon exhibited by elements Z is isotopy. (ii) Difference in the number of neutrons accounts for the difference in mass number. (iii) 75% ( \(^{35}_{17} Z\) )+ \(^{37}_{17} Z\); 100 - 75 = 25% 75% \(^{35}_{17} Z\) + 25% \(^{37}_{17} Z\) (\(\frac{75}{100} \times 35\)) + (\(\frac{25}{100} \times 37\)) = 26.25 + 9.25 = 35.5 (d)(i) I. CO\(_{2(g)}\) collected by downward delivery or upward displacement of air. II. HC\(I_g\) collected by downward delivery or upward displacement of air. III. H\(_{2(g)}\) collected by upward delivery or downward displacement of air. (ii) Reason for answer stated in d(i)I & d(i)II. I. CO\(_{2(g)}\) is heavier / denser than air. II. HC\(l_g\) is heavier / denser than air.

(a)(i) Structure of two isomers of X (ii) Catalytic cracking (iii) C\(_4\)H\(_8\) (12 - 8) = 4, (26 - 18) = 8 (iv) Name of Isomers drawn in a(iii) are: (A) But - 1- ene (B) But - 2 - ene (C) 2-methyl propene (v) Balanced equation for the reaction between X and hydrogen. C\(_4\)H\(_8\) + H\(_2\) ---> C\(_4\)H\(_{10}\) (b) Test for fats: A small amount of the substance placed on a filter paper then rub or warm or melt on the filter paper. Formation of a translucent spot on the filter paper shows or indicates the presence of fats presence of fat or a small amount of the substance treated with Sudan III reagent/or Add Sudan III to the sample. Observation of a red colour shows the presence of fat. (c) Molar mass of H\(_2\)SO\(_4\): [(1 x 2) + 32 + (4 x16)] = 2 + 32 + 64 = 98 — 98g mol\(^{-2}\) 1 mole of O\(_{2(g)}\) --> 2 moles of H\(_2\)SO\(_2\) 1.5 mole of O\(_{2(g)}\) --> (2 x 1.5) moles of H\(_2\)SO\(_4\) 3 moles of H\(_2\)SO\(_4\) Mass of 3 moles of H\(_2\)SO\(_4\) = 3 x 98 = 294g. (d) (i) Enthalpy changes for reactions in their increasing magnitude. \(\bigtriangleup\)H\(_2\) < \(\bigtriangleup\)H\(_1\) < \(\bigtriangleup\)\(_3\) or \(\bigtriangleup\)H\(_2\) \(\bigtriangleup\)H\(_1\) \(\bigtriangleup\)H\(_3\), or \(\bigtriangleup\)H\(_3\) > \(\bigtriangleup\)H\(_1\) > \(\bigtriangleup\)H\(_2\) < lesser than > greater than (ii) The explanation in the order of arrangement in (d) (i): Neutralization involves the combination of H\(^+\) and OH\(^-\) ions to give a specific amount of energy. The greater the ionization, the greater the energy given off \(\bigtriangleup\)H\(_2\) involves a weak acid and a weak base/weak electrolyte. \(\bigtriangleup\)H\(_1\), involves a stronge base and a weak acid. \(\bigtriangleup\)H\(_3\) involves a strong acid and a strong base. (e) (i) Cu\(_{(s)}\) can conduct electricity, (ii) NaH\(_{(g)}\) , BeCl\(_{2(s)}\), HF\(_{(l)}\) are soluble in water.

(a) Industrial preparation of ammonia (NH\(_{3(g)}\)) (i) Dry nitrogen (N\(_{2(g)}\)) mixed with dry hydrogen (H\(_{2(g)}\)) in the volume proportion of 1 : 3 over a pressure of 200 — 500 atm at temperature of 450^\circC — 500^\circC. Finely divided iron used as catalyst. (ii) N\(_{7(g)}\) 3H\(_{2(g)}\) 2NH\(_{3(g)}\) Balanced equation of the reaction written above. (iii) Way of increasing the yield of ammonia (NH\(_{3(g)}\)) is continuous removal of ammonia as it is formed or liquefying of the ammonia gas at a low temperature or high pressure. (iv) Two uses of ammonia: (1) used in manufacture of fertilizers. (2) used as a precipitating agent. Other uses: Manufacture of trioxonitrate (v) acid; manufacture of sodium trioxocarbonate. (iv) textiles, pesticides, used in detergent/cleasing agent, manufacture of plastics, laundry works, pharmaceuticals as a refrigerant, softening temperarily hard water, removal of insect stings. (b)(i) Chemical test for hydrogen H\(_{2(g)}\), a lighted wooden splint is brought to the tip of a test tube containing the gas. The gas gives a pop sound shows the presence of Hydrogen H\(_{2(g)}\). (ii) CO\(_{2(g)}\), The gas bubble through limewater Ca(OH)\(_{2}\) solution. The lime water turns milky shows the presence of CO\(_{2(g)}\) (iii) Oxygen O\(_{2(g)}\), a glowing (wooden) splint dipped into a test tube of the gas. The (wooden) splint rekindles or relights shows that O\(_{2(g)}\) is present. (c)(i) Composition of water gas: Carbon (II) oxide (C\(O_g\)) and Hydrogen gas H\(_{2(g)}\) (ii) 2 Uses of water gas: (1) industrial manufacture of hydrogen. (2) industrial manufacture of methanol butanol. (3) used as fuel. (d) A simple experiment to determine type of hardness in a sample of water. Sample of water boiled, soap added and shaken, if it forms lather easily it is temporary hardness, if it forms lather with difficultly or does not form lather easily it is permanent hardness.