Burette readings (initial and final) must be given to two decimal places. Volume or pipete used must also be recorded but no account of experimental procedure is required. All calculations must be done in your answer book.
A is a solution containing 12.0g dm\(^{-3}\) NaHSO\(_4\) NaHSO\(_4\) P is a solution containing NaOH
(a) Put A into the burette and titrate it against 20.0cm\(^3\) or 25.0m\(^3\) portions of B using methyl orange as an indicator. Repeat the titration to obtain consistent titres. Tabulate your readings and calculate the average volume A used. The equation for the reaction involved in the titration is ;
NaHSO\(_{4(aq)}\) + NaOH\(_{(aq)}\) \(\to\) Na\(_2\)SO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\)
[H 1.00, O = 16.0; Na = 23.0, S = 32.0]
(b) From your results and the information provided above calculate the:
(i) concentration of A in mol dm\(^{-3}\)
(ii) concentration of B in mol dm\(^{-3}\)
(iii) mass of Na\(^+\) formed in solution during the titration.
Credit will be given for strict adherence to the instructions, for observations precisely recorded, and for accurate inferences. All tests, observations, and inferences must be clearly entered in your answer book, in ink, at the time they are made.
C and D are inorganic salts. X is a solution of an inorganic compound. Carry out the following exercises on C, D and X. Record your observations and identity any gas(es) involved. State the conclusion drawn from the result or each test.
(a)(i) Add about 5 cm\(_3\) of distilled water to C in a test tube and shake thoroughly, Divide the resulting solution into two portions.
(ii) Put about 2cm\(^3\) of X into a separate test tube and add the first portion of solution in (a)(i) To the second portion of the resulting solution in (a)(i), add few drops of BaCl\(_{2(aq)}\) followed by excess dil. HCI.
(b) Add about 10 cm of distilled water to D in a boiling tube and shake thoroughly.
(i) To about 2 cm\(^3\) portion of the resulting solution in a test tube, add NaOH\(_{(aq)}\) in drops and then in excess
(ii) To another 2 cm\(^3\) portion of the resulting solution add few drops of K\(_2\)CrO\(_{4(aq)}\)
(a) An aqueous solution of salt Q was added to excess Sodium trioxocarbonate (V) solution in a test tube. There was effervescence, the test tube became warm and a white precipitate was observed. State three inferences that could be drawn from these observations.
(b) Consider the following salts: NH\(_4\)CI; PbSO\(_4\); NaHCO\(_3\), Cu(NO\(_3\))\(_2\) and ZnCO\(_3\). Select from the list, the salt(s) which;
(i) do not/does not readily dissolve in water;
(i) produce(s) effervescence with dilute mineral acids;
(ii) decompose(s) on heating
(iv) dissolves(s) in water to form an alkaline solution;
(v) sublime(s) on heating.
(a) Name one product of destructive distillation of coal that is (i) solid (ii) liquid; (iii) gas.
(b) (i) What is the major component of synthetic gas? (ii) Give one reason why synthetic gas is not a major source of air pollution.
(c) (i) Write a balanced chemical equation for the complete combustion of carbon. (ii) State two: I. physical; II. chemical properties of the product in (c)(i).
(d) (i) Name two allotropes of carbon that are I. crystalline, II. amorphous. (ii) State one use of each of the allotropes named in (d)(i).
(e) (i) By means of balanced chemical equations only, outline the process of manufacture of H\(_2\)SO\(_4\), by contact process.
(ii) State the function of H\(_2\)SO\(_4\) in each of the following reaction equations:
I. C\(_2\)H\(_5\)OH\(_{2(l)}\) \(\to\) C\(_2\)H\(_{4(g)}\);
II. Pb(NO\(_{3(g)}\) + H\(_2\)SO\(_{4(g)}\) —> PbSO\(_{4(s)}\) + 2HNO\(_{3(aq)}\)
(a (i) Explain why water is referred to as a universal solvent.
(ii) Give one chemical test for water. H\(_2\)SO\(_4\)
(b) A current of 1.25A was passed through an electrolytic cell containing dil. for 40 minutes.
(i) Write (ii) Calculate the volume of gas produced at the anode at s.t.p. (1F = 96,500 C, Molar Volume of gas at s.t.p. = 22.4 dm\(^3\) mol\(^{-3}\) ]
(C) Consider the reaction represented by the following equation: Au\(_{(s)}\) + Cl\(_{2(g)}\) \(\to\) AuCl\(_{3(s)}\)
(I) Balance the equation
(ii) If 1.2509 of Au and 1.744g of Cl\(_2\) were mixed
I. determine which of the reactants is in excess II. calculate the excess amount [Au = 197.0, CI = 35.5]
(a)(i) Give the two reasons why soda lime is used instead of caustic soda in the preparation of methane.
(ii) List two physical properties of methane.
(iii) A hydrocarbon with a vapour density of 29 contains 82.76% carbon and 17.24% hydrogen. Determine the: I. empirical formula; II. molecular formula of the hydrocarbon. [ H = 1.00 C = 12.00 ]
(b)(i) What is meant by the term isomerism?
(ii) Draw the structures of the two isomers of the compound with the molecular formula C\(_2\)H\(_6\)O.
(iii) Give the name of each of the isomers in (b)(ii).
(iv) State the major difference between the isomers.
(c) Give three deductions that could be made from the qualitative and quantitative analysis of a given organic compound.
(d) Give one chemical test to distinguish between propene and propane.
(a) (i) Define a base according to Arrhenius concept.
(ii) Give one example of an Arrhenius base.
(iii) Identify each of the following substances in aqueous solutions as strong electrolyte, non-electrolyte or weak electrolyte.
I. C\(_{12}\)H\(_{22}\)O\(_{11}\) II. NH\(_3\) Ill. NaOH
(iv) Write a balanced equation to represent the reaction between CH\(_3\)COOH and KOH.
(b) Calculate the volume of 0.500 mol dm\(^{-3}\) HCI required to neutralize 20.00 cm\(^3\) of 0.300 mol dm\(^{-3}\) NaOH.
(c) Give the IUPAC name of each of the following salts: (ii) NaOCI; (iii) Mg(HCO\(_3\))\(_2\).
(d)(i) Define the term standard solution.
(ii) Consider the following compounds: NaOH and Na\(_2\)CO\(_3\). Which of the compounds is suitable for the preparation of a standard alkaline solution? Give reason for your answer
(iii) Fe completely reacted with dilute HCI.
I. Write an equation for the reaction
II. If 3.08g of Fe completely reacted with 50.0 cm\(^3\) of 2.20 mol dm\(^{-3}\) HCI, calculate the relative atomic mass of the metal.
(a) (i) Define saturated solution.
(ii) Tha solubility of KNO\(_3\) at 20°C was 3.00 mol dm\(^{-3}\) If 67.0g of KNO\(_3\) was added to 250 cm\(^{-3}\) of water and stirred at 20°C, determine whether the solution formed was saturated or not at that temperature. [ KNO\(_3\) = 101.0 ]
(b) (i) Distinguish between dative bond and covalent bond.
(ii) Explain why sugar and common salt do not conduct electricity in the solid state.
(iii) State the type of intermolecular forces present in: I. hydrogen fluoride; II argon.
(iv) Consider the compounds with the following structures. S – H —- N and O – H —- N In which of the compounds is the hydrogen bend stronger? Give reason for your answer.
(c) (i) State Dalton’s Law of Partial Pressure.
(ii) If 200cm of carbon (IV) oxide were collected over water at 18°C and 700 mmHg, determine the volume of the dry gas at s.t.p. [ standard vapour pressure of water at 18°C = 15 mmHg]
(a) i) Give the name and nature of the radiations that are emitted during radioactivity.
ii) State two differences between chemical reaction and nuclear reaction.
iii) Balance the following nuclear reactions and identify X and Y.
I. \(^{212}_{84} PO\) \(\to\) \(^{208}_{82} Pb\) + X
II \(^{137}_{55}Cs\) \(\to\) \(^{137}_{55}Ba\) + Y
(b) The electron configuration of an element X is: 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^5\)
(i) Deduce the atomic number of X.
(ii) To what group does X belong?
(iii) Give two properties of the group to which the element X belong.
(iv) Identify element X by name.
(v) Write a balanced equation to represent the reaction between the element X and hot concentrated NaOH.
(c)(i) Explain why: I. graphite is used as a lubricant; II. diamond is used as an industrial cutting tool.
(ii) Write an equation to represent the reaction between aqueous HCI and NH\(_3\) solution.
(iii) Name the type of reaction represented by the equation.
Which of the following metals exists as liquid at ordinary temperature?
- A. Copper
- B. Gold
- C. Mercury
- D. Silver
Which of the following substances cannot be classified as a heavy chemical?
- A. AgNO3
- B. CaO
- C. CaOCI2
- D. H2SO4
The main function of limestone in the blast furnance is to
- A. act as a reducing agent
- B. act as a catalyst
- C. remove impurities
- D. supply carbon (IV) oxide
Compound N reacts with sodium metal to produce a gas that gives a ‘pop’ sound with a burning splint N also react with ethanoic acid to give a sweet smelling liquid. Compound N is an
- A. alkanol
- B. alkanoate
- C. alkane
- D. alkanoic acid
An organic compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. What is the empirical formula of the compound? [O = 16.0, C = 12.0, H = 1.0]
- A. C2HO
- B. CHO
- C. CH2O
- D. CHO2
The IUPAC name of C2H6COOC2,/sub>H6 is
- A. ethyethanoate
- B. ethylproanoate
- C. propylethanoate
- D. propylpropanoate
The products of fermentation of sugar are
- A. carbon(IV) oxide and water
- B. ethanol and carbon (IV) oxide
- C. ethanol and water
- D. ethanol and enzymes
An advantage of detergent over soap is that detergents
- A. are readily available
- B. are in powerdered from
- C. are non-biodegradable
- D. lather readily with water
Fact and oils are used as raw materials in the following industries except
- A. paint industry
- B. plastic industry
- C. margarine industry
- D. cosmetics industry
The quantity of electricity required to discharge 1 mole of univalent ion is
- A. 9,600 C
- B. 48,250 C
- C. 96,500 C
- D. 193,00 C
What is the change in oxidation number of manganes in the reaction represented by the following equation? MnO–4(aq) + 8H+(aq) + 5e– → Mn2+(aq) + 4H2O(l)
- A. +3 to + 2
- B. + 4 to + 2
- C. + 5 to + 2
- D. + 7 to 2
Which of the following statements about the electrolysis of CuSO4(aq) using copper cathode and platinum anode is not correct?
- A. Copper is deposited at the cathode
- B. Oxygen is liberated at the anode
- C. it is used for the purification of copper
- D. The solution becomes acidic