23/04/2020Senior Class WAEC/NECO/UTME Mock Exams(Chemistry) 0Comments by Gate Academy Please, fill out the information below to continue. NAME EMAIL PHONE NUMBER 1. When an atom gains an electron, it becomes A non-metal atom Positively charged Chemically inactive A cation An anion2. An atom is electrically neutral if the number of Protons is equal to the number of neutrons Protons is equal to the number of electrons Electrons is equal to the number of neutrons Neutrons is equal to the atomic number3. Which of the following is not a type of elements? Metalloids Metals Non Metals Gases4. What is the pattern of the degree of electropositivity of elements in the periodic table? Decreases down a group and across period Decreases across a period Increases across a period Remains constant across a period Remains constant down a group5. H2(g) + I2(g) ↔ 2HI(g) In the reaction, increasing the pressure will favour the forward reaction favour the backward reaction increase the concentration of HI decrease the concentration of HI have no effect on the equilibrium position6. Which of the following is not an isotope of hydrogen? Deuterium Tritium Protium Proton7. The main constituents of petroleum are alkynes gases alkanes hydrocarbons solids8. What current in amperes will deposit 2.7g of aluminium in 2 hours?[Al = 27, 1F = 96500C] 8 4 32 28 169. Consider the reaction represented by the equation:H2(g) + I2(g) ↔ 2HI(g) ΔH = -veWhich of the following statements about the equation is correct? the addition of a catalyst will change the equilibrium position increase in pressure will favour the forward reaction increase in temperature will favour the forward reaction pressure will have no effect on the production of HI(g) the removal of HI(g) formed will favour the backward reaction10. The bleaching of wood pulp for making paper by sulphur(iv)oxide is a process of vulcanization desulphurisation oxidation refining reduction11. Which of the listed molecules has two lone pairs of electrons? ammonia benzene carbon(iv)oxide hydrogen gas water12. When hydrogen sulphide gas is passed through an acidified solution of potassium heptaoxo dichromate(vi), the orange colour changes to green. This is because the hydrogen sulphide is a good oxidizing agent chromium(vi) ion is oxidized +6 state of Cr is reduced to +3 state sulphide ion changes to sulphur atom +3 state of Cr is oxidized to +6 state13. What would happen if more heat is applied to the following system at equilibrium?X2(g) + 3Y2(g) ↔ 2XY3(g); ∆H = -xKj/mol More of XY3 will decompose The yield of XY3 will increase The forward reaction will go to completion More of X2 will react14. When ammonium chloride is dissolved in water in a test tube, the test tube feels cooler showing that? The process is endothermic Sublimation has occurred The solution is unsaturated Ammonia gas is evolved15. Which of the following substances decompose when an electric circuit is passed through it? glucose solution dilute hydrochloric acid zinc rod tetra chloromethane16. An exothermic reaction is one which involves Attainment of dynamic equilibrium Evolution of gas as it proceeds Positive change in value of enthalpy Loss of heat to the surroundings17. In galvanizing iron, the metal which coats the iron is zinc tin gold aluminium silver18. P, Q, R, S are metals in the same period in the periodic table but in groups 3, 4, 5, 6 respectively. Which of them loses electrons least reactively? R Q P S19. The catalyst generally used in the synthesis of methanol from carbon(ii)oxide and hydrogen is nickel vanadium(v)oxide platinum copper-zinc oxide zinc oxide20. The rate of production of hydrogen gas from the reaction between zinc granules and hydrochloric acid can be increased by Carrying out the reaction at a higher pressure Cooling the reaction mixture Using zinc powder instead of granules Using zinc rod instead of zinc granules21. The natural sources of hydrocarbons are:I. CoalII. Natural gasIII. PetroleumIV. Organic compounds I, II, III and IV IV Only I,II and III Only III and IV Only I and II Only22. Which of the following is NOT a halogen? bromine silicon iodine astatine fluorine23. Which of the following gives a yellow precipitate of a metallic derivative when reacted with ammoniacal silver trioxonitrate(v) at room temperature? ethanal propyne butene propane ethanol24. When excess ammonia is added to an aqueous copper(ii)tetraoxosulphate(vi), a deep blue solution of copper(ii)tetraamine is formed. The type of bond in copper(ii)tetraamine is covalent bond van der waals hydrogen bond coordinate covalent bond ionic bond25. Which of the following is true of Ionisation energy? it is the energy due to electron gain the higher the screening effect, the higher the ionization energy it increases down the group it is unaffected by nuclear charge it increases across the period26. Substance Q reacts with cold water to form a solution which turns red litmus blue.Substance Q could be? Phosphorus Calcium Nitrogen Sulphur27. Lemon is a source of ................acid lactic ascorbic ethanoic citric amino28. The isotope of hydrogen with relative atomic mass of 2 is? Tritium Deuterium Protium Hydride29. What is the composition of soap? Potassium salt with fatty acids Sodium salt with fatty acids. Sodium and Potassium salt mixed with chemicals Both a & b30. Helium is preferred to hydrogen in filling balloons because hydrogen?is diatomicis inflammableExhibits isotopyis a component of water31. Water gas is a mixture of? Carbon(ii)oxide and hydrogen Carbon(iv)oxide and hydrogen Nitrogen and Hydrogen Carbon and Hydrogen32. The gas given off when calcium is added to water is Hydrogen Oxygen Nitrogen(iv)oxide Calcium oxide33. Which of these is not a property of a system that is in a state of chemical equilibrium? The change in entropy is zero It must take place in a closed system The value of change in free energy is zero It is a reversible system34. In which of the following compounds does sulphur have an oxidation number of +4 H2S207 Na2SO3 H2S H2SO4 SO335. Dilute HCl produces a gas with each of the following compounds EXCEPT sodium trioxosulphate(iv) calcium trioxocarbonate(iv) copper(ii)trioxocarbonate(iv) sodium tetraoxosulphate(vi) iron(ii)sulphide36. What will be the effect of increase in pressure on the following system at equilibrium?2NH3(g) ↔ N2(g) + 3H2(g) Activation energy will decrease The reaction will go to completion The forward reaction will be favoured The concentration of ammonia will increase37. Natural rubber is a ________ which is having high elasticity. Material Chemical using carbon as main compound Substance Elastomer38. In which form is natural petroleum found? Kerosene Crude Oil Gasoline Tar39. The Azimuthal quantum number which corresponds to the f-orbital is 2 0 6 3 140. What is detergent? A liquid solution A liquid sovent A liquid surfactant A liquid soluble41. The following are diatomic except? Hyrdrogen Nitrogen Fluorine Helium42. 15dm³ of a gas at s.t.p. in a tube was pressed by a piston whose pressure was increased to twice its original value at the same temperature. The volume of the gas in dm³ at this new pressure is 12.0dm³ 5.0dm³ 30.0dm³ 10.0dm³ 7.5dm³43. The following metals are usually extracted by the method of electrolysis EXCEPT magnesium sodium iron aluminium potassium44. Factors affecting a system in chemical equilibrium include all these except Catalyst Temperature Pressure Concentration45. Which of the listed molecules has two lone pairs of electrons? hydrogen gas carbon(iv)oxide ammonia water benzene46. Substances which absorb water from the atmosphere without dissolving in them are said to be Hydrated Hygroscopic Anhydrous Deliquesence47. The catalyst generally used in the synthesis of methanol from carbon(ii)oxide and hydrogen is nickel vanadium(v)oxide platinum zinc oxide copper-zinc oxide48. In which of the following compounds does sulphur have an oxidation number of +4 Na2SO3 H2S207 H2S H2SO4 SO349. Which of the following decreases when a given mass of gas is compressed to half its initial volume? Atomic radius of each particle Frequency of collisions Number of molecules present Average intermolecular distance50. A finely divided form of a metal burns more readily in air than the rod form because the rod has Higher molar mass Protecting oxide coating Different chemical properties Smaller surface area51. Which of the following is true of gamma (γ) rays? They are negatively charged travel at very low speed are neutral are positively charged have no ionizing power52. Which of the following statements is NOT correct about the compound represented below?COOH|COOH its name is ethanedioic acid it produces effervescence with saturated NaHCO3 solution it is a di-carboxylic acid its b.p is higher than that of the corresponding alkane it has a basicity of 453. What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?[H=1, O=16] 8.0g 36.0g 72.0g 54.0g54. An element Y has the electronic configuration1s2 2s2 2p6 3s2 3p4 How many lone pair of electrons are present in element Y? 2 4 1 355. Dynamic equilibrium describes a situation where? Reactants are converted to products Reaction gives back the reactant A concentration of reactants and product is equal Both forward and reverse reactions proceed at the same rate56. Which acid is present in lemon? marlic acid citric acid lactic acid tartaric acid57. Radioisotopes can be used:I. As radioactive tracersII. for sterilizationIII. in photographyIV. for dyeing I, II and III Only I, II, III and IV III and IV Only IV Only I and II Only58. 15dm³ of a gas at s.t.p. in a tube was pressed by a piston whose pressure was increased to twice its original value at the same temperature. The volume of the gas in dm³ at this new pressure is 12.0dm³ 10.0dm³ 7.5dm³ 5.0dm³ 30.0dm³59. A feasible cell was constructed by joining the two half cells below:Cu2+ (aq) + 2e- → Cu(s); Eꝋ = + 0.34vZn2+ (aq) + 2e- → Zn(s); Eꝋ = - 0.76vWhat is the standard e.m.f of the cell? - 0.42v - 1.1v + 1.1v + 0.42v60. The following salts can be prepared by a double decomposition reaction EXCEPT BaCO3 KCl AgCl PbCl2 BaSO461 out of 60Time is Up!