SS 3 CHEMISTRY PAST QUESTIONS (WAEC/NECO) HomeWAEC/NECO Exam Past QuestionsSS 3 CHEMISTRY PAST QUESTIONS (WAEC/NECO) 0% SSCE/NECO/GCE (CHEMISTRY PAST QUESTIONS) CHEMISTRY PAST QUESTIONS APP Questions will be picked at random from the question bank. You can use the NEXT button to move to the next question, use the PREV button to move to the previous question, the CLEAR button to clear any answer of your choice and you have the FINISH button to end the exam if you choose to. Any question not answered before the end of the exam time, will be marked as wrong and the exam will end by itself. so try to attempt all questions on time. Goodluck! 1 / 80 Category: CHEMISTRY PAST QUESTIONS One mole of a compound M(HCO3)2 has a mass of 162g. Calculate the relative atomic mass of M. [H = 1, C =12, O = 16] 53 101 122 40 2 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following lowers the activation energy of a chemical reaction? Freezing mixture Water Reducing agent Catalyst 3 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following features of a human skeleton can be determined by carbon-dating? Height Mass Age Race 4 / 80 Category: CHEMISTRY PAST QUESTIONS What volume of hydrogen is produced at s.t.p. When 2.60 g of zinc reacts with excess HCI according to the following equation? Zn(s) + 2HCI(aq) → ZnCI 2(aq) + H2(g) [Zn = 65; 1 mole of a gas occupies 22.4dm3 at s.t.p] 0.896dm 3 8.62dm 3 5.82dm 3 0.040dm 3 5 / 80 Category: CHEMISTRY PAST QUESTIONS Chemical equilibrium is attained when concentrations of the reactants and products remain constant concentrations of the products are greater than those of the reactants reactants stop forming the products reactants in the system are used up 6 / 80 Category: CHEMISTRY PAST QUESTIONS Consider the following equation: Ag+ (aq) + CI-(aq) → Ag+CI- (s) ; ∆H = _65.7 kJmol-1. From the equation, it can be deduced that the reaction is endothermic and occurs at high temperature activation energy is high and a catalyst is required a solid is formed and heat is evolved direct combination is involved and the reaction is endothermic 7 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following substances decomposes when an electric current is passed through it? Hydrochloric acid Glucose solution Tetrachlormethane Zinc rod 8 / 80 Category: CHEMISTRY PAST QUESTIONS What type of reaction is involved when wood shavings produce a brown gas with concentrated HNO3? Nutralization Redox reaction Destructive distillation Dehydration 9 / 80 Category: CHEMISTRY PAST QUESTIONS Given that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible? R + P+ → P + R+ S + Q+ → Q + S+ S + P+ → P + S + Q + S+ → S + Q+ 10 / 80 Category: CHEMISTRY PAST QUESTIONS What mass of copper would be deposited by a current of 1. 0 ampere passing for 965 seconds through copper (ll) tetraoxosulphate (IV) solution? [Cu = 63.5; 1F = 96500C] 18g 6.35g 0.318g 0.635g 11 / 80 Category: CHEMISTRY PAST QUESTIONS Calcium atom ionizes by sharing two electrons losing two electrons gaining two protons gaining two electrons 12 / 80 Category: CHEMISTRY PAST QUESTIONS In the Periodic Table, the elements that loss electrons most readily belong to Group 111 A Group 1 A Group 11 A Group V11 A 13 / 80 Category: CHEMISTRY PAST QUESTIONS Petrol consists mainly of alkanoates alktanols polymers hydrocarbons 14 / 80 Category: CHEMISTRY PAST QUESTIONS What is the effect of using vanadium (V) oxide as catalyst in the reaction represented by the following equation? 2SO2 + O2 ⇌ 2SO3; ∆H = - xKJmol-1 Increases the collision rate of reactant particles Reduces the time for attainment of equilibrium Decreases the value of ∆H Shifts equilibrium position to the right 15 / 80 Category: CHEMISTRY PAST QUESTIONS 0.10 mol dm-3 NaCI conducts electricity better than 0.10 mol dm-3 CH3COOH because the solution of NaCI has a lower molar mass contains more ions has a higher pH is neutral to litmus 16 / 80 Category: CHEMISTRY PAST QUESTIONS Pauli Exclusion Principle is related to collision theory of reaction rates reversiblility of equlibrium reactions quantum numbers of electrons electronegativity values of elements 17 / 80 Category: CHEMISTRY PAST QUESTIONS What will be the effect of increase in pressure on the following system at equilibrium? 2NH2(g) N2(g) + 3H2(g) the forward reaction will be favoured the concentration of ammonia will increase the reaction will go to completion Activation energy will decrease 18 / 80 Category: CHEMISTRY PAST QUESTIONS Helium is preferred to hydrogen in filling balloons because hydrogen is a component of water is diatomic exhibits isotopy is inflammable 19 / 80 Category: CHEMISTRY PAST QUESTIONS What is the oxidation number of nitrogen in AI(NO3)3? + 1 + 6 + 3 + 5 20 / 80 Category: CHEMISTRY PAST QUESTIONS The liquid product of the destructive distillation of coal is kerosene ammoniacal liquor paraffin oil ethanol 21 / 80 Category: CHEMISTRY PAST QUESTIONS A sheet of paper is placed in the path of a beam from a radioactive source. The emissions that pass through the paper consist of beta particles and gamma rays alpha particles and gamma rays alpha and beta particles alpha particles only 22 / 80 Category: CHEMISTRY PAST QUESTIONS An exothermic reaction is one which involves attainment of dynamic equilibrium loss of heat to the surrounding positive change in value of enthalpy evolution of gas as it proceeds 23 / 80 Category: CHEMISTRY PAST QUESTIONS A concentrated solution containing H+, Cu2+,OH- and CI- was electrolysed using platiunm electrodes which of the ions will be discharged at the cathods? H+ CI- Cu2+ OH- 24 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following non-metals reacts most readily with metals? Carbon Sulphur Nitrogen Chlorine 25 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following will produce oxygen and hydrogen during its electrolysis using platinum electrode? Concentrated hydrochloric acid Aqueous copper (ll) tetraoxosulphate (IV) Dilute sodium chloride solution Glucose solution 26 / 80 Category: CHEMISTRY PAST QUESTIONS Two radioactive elements Q and S have half-life periods of 10 hours and 20 hours respectively. Therefore S is more stable than Q S decays faster than Q Q emits fewer particles than S Q is twice as stable as S 27 / 80 Category: CHEMISTRY PAST QUESTIONS Equal volumes of CO2 cnd CO at s.t.p have the same number of molecules mass rate of diffusion density 28 / 80 Category: CHEMISTRY PAST QUESTIONS What is the value of x in the following equation? Cr2O72- + 14H+ + xe- → 2Cr3+ + 7H2O 6 1 12 8 29 / 80 Category: CHEMISTRY PAST QUESTIONS The type of chemical bond that exists between potassium and oxygen in potassium oxide is metallic covalent dative ionic 30 / 80 Category: CHEMISTRY PAST QUESTIONS A reaction is represented by the equation below. A2(g) + B2(g) 2AB(g); ∆H = +X kJmol-1 Which of the following statements about the system is correct? The forward reaction is exthermic At equilibrium increase in temperature favours the reverse reaction Pressure has no effect on the equilibrium mixture The reaction goes to completion at equilibrium 31 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following occurs when a solution of CuSO4 is electrolysed using copper electrodes? Both electrodes gain electrons The cathode becomes coated with copper The anode increases in mass The blue colour of the solution fades gradually 32 / 80 Category: CHEMISTRY PAST QUESTIONS The spontaneity of a chemical reaction is determined by the change in the concentration of the reactants temperature of the system pressure applied to the system free energy of the system 33 / 80 Category: CHEMISTRY PAST QUESTIONS Consider the reaction represented by the following equation: H2(g) + 12(g) → 2HI(g). The number of effective collisions of molecules of the reactants decreases as the pressure increased a catalysty is intoduced into the system the temperature is raised the volume of the system is increased 34 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following properties increases down a group in the Periodic Table? Ionization energy Electronegativity Electon affinity Atomic radius 35 / 80 Category: CHEMISTRY PAST QUESTIONS Aluminium is extracted from magnetite bauxite cryolite cassiterite 36 / 80 Category: CHEMISTRY PAST QUESTIONS Elactrostatic force of attraction between sodium ion and halide ion is greatest in NaF NaI NaCI NaBr 37 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following contains co-ordinate covalent bond? CH4 HCI Na+CI NH4 38 / 80 Category: CHEMISTRY PAST QUESTIONS A finely divided from of a metal burns more readily in air than the rod from because the rod has different chemical properties protective oxide coating smaller surface area higher molar mass 39 / 80 Category: CHEMISTRY PAST QUESTIONS A mixture of calcium chloride and calcium trioxocarbonate (IV) in water can be separated by filtration distillation sublimation evaporation 40 / 80 Category: CHEMISTRY PAST QUESTIONS What is the function of sulphur (IV) oxide in the reaction represented by the following equation? SO 2(aq) + 2H2S(g) → 3S (s) + 2H 2O (l) Oxidising agent Dehydrating agent Acid Bleaching agent 41 / 80 Category: CHEMISTRY PAST QUESTIONS What does ∆H represent in the following equation ? Cl(g) + e- → CI- (g); ∆H = - 363 kJ mol-1 lonization energy Heat of atomization Electron affinity Dissociation energy 42 / 80 Category: CHEMISTRY PAST QUESTIONS Electrovalent compounds are characterized by high molar mass high melting point strong oxidizing ability solubility in ethanol 43 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following pairs of reagents recat to produce hydrogen? Zinc and concentrated trioxonitrate (V) acid Magnesium and dilute tetraoxosulphate (VI) acid Water and calcium dicarbide Copper and dilute hydrochloric acid 44 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the orbitals 4s, 4p, 4d and 4f has the lowest energy? 4p 4d 4f 4s 45 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following compounds dissolves in water to give an alkaline solution? Sulphur (IV) oxide Sodium chloride Ammonium chloride Potassium oxide 46 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following increases as boiling water changes to steam? temperature of the system activation energy number of molecules degree of disorder in the system 47 / 80 Category: CHEMISTRY PAST QUESTIONS The atoms of four elements are represented as 20Q, 16R, 10S and 8T Which of the elements would be unreactive? R Q T S 48 / 80 Category: CHEMISTRY PAST QUESTIONS Metals are said to be malleable because they are good conductors of electricity are good conductors heat can be alloyed can be beaten into sheets 49 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following will displace copper from a solution of copper (ll) salt? Magnesium Aluminium ions Silver Zinc ions 50 / 80 Category: CHEMISTRY PAST QUESTIONS Substances which absorb water from the atmosphere without dissolving in it are said to be insolube hygroscopic anhydrous hydrated 51 / 80 Category: CHEMISTRY PAST QUESTIONS The property of calcium chloride which makes it useful as a drying agent is that it is deliquescent ionic a strong electrolyte a normal salt 52 / 80 Category: CHEMISTRY PAST QUESTIONS If the solubility of KHCO3 is 0.40 mole dm-3 40.0g 100.0g 4.0g 10.0g 53 / 80 Category: CHEMISTRY PAST QUESTIONS Rusting of iron is an example of displacement reaction deliquescence decomposition redox reaction 54 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following movements can be described as random motion? wheelbarrow being pushed car travelling on a straight line gas molecules colliding in a flask planets going round the sun 55 / 80 Category: CHEMISTRY PAST QUESTIONS What is the shape of a molecule of CCI4? Trigonal planar Pyramidal Tetrahedral Linear 56 / 80 Category: CHEMISTRY PAST QUESTIONS The crystal layers in graphite are held together by electrostatic forces covalent bonds van der Waals' forces hydrogen bonds 57 / 80 Category: CHEMISTRY PAST QUESTIONS Dehydration of ethanol produces propan-1,2,3-triol ethanoic acid ethene ethanal 58 / 80 Category: CHEMISTRY PAST QUESTIONS Gas molecules are said to be perfectly elastic because they move about in straight lines they collide without loss of energy the distances between them are negligible the volume occupied by them is negligible 59 / 80 Category: CHEMISTRY PAST QUESTIONS Exhaust fumes discharged from a smoky vehicle gradually become invisible as a result of diffusion emission combustion absorption 60 / 80 Category: CHEMISTRY PAST QUESTIONS It can be concluded that gastric juice contains enzymes has pH value of 7 is a mixture is acidic 61 / 80 Category: CHEMISTRY PAST QUESTIONS What is responsible for metallic bonding? Attraction between positive and negative ions Attraction between the atomic unclei and cloud of electrons Sharing of electrons between the metal atoms transfer of electrons from one atom to another 62 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following compounds dissolves in water to form a solution with pH below 7? Sodium trioxocarbonate (IV) Sodium tetraoxosulphate (VI) Potassium hydroxide Ammonium chloride 63 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following methods is suitable for the preparation of an insoluble salt? Neutralisation Double decomposition Action of an acid on a trioxocarbonate (IV) Action of an acid on a metal 64 / 80 Category: CHEMISTRY PAST QUESTIONS When alkanols react with sodium, the ga evolved is oxygen ethyne methane hydrogen 65 / 80 Category: CHEMISTRY PAST QUESTIONS If an element with high electron affinity combines with another element with low ionization energy the bond formed will be mainly ionic covalent metallic dative 66 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following procedures is suitable for identifying the food colouring added to a pastry sample? The blue colour of the solution fades gradually The cathode becomes coated with copper Both electrodes gain electrons The anode increases in mass 67 / 80 Category: CHEMISTRY PAST QUESTIONS Pipe-borne water is usually chlorinated in order to coagulate sediments in the water improve the teste of the water remove the hardness in the water clear kill harmful bacteria in the water 68 / 80 Category: CHEMISTRY PAST QUESTIONS Elements which belong to the same group in the Periodic Table are characterized by difference of 14 atomic mass units between successive members difference of +1 in the oxidation numbers of successive members presence of the same number of outermost electrons in the respective atoms presence of the same number of electron shells in the respective atoms 69 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following would dissolve in warm dilute H2SO4 without effervescence, to give a blue solution? Copper turnings Copper (ll) trioxocarbonate (IV) Copper alloy Copper (ll) oxide 70 / 80 Category: CHEMISTRY PAST QUESTIONS Chlorine atom forms CI by Gaining one electron Donating lone pair of electrons Sharing one electron Losing one electron 71 / 80 Category: CHEMISTRY PAST QUESTIONS The presence of unpaired electrons in an atom of a transition metal gives rise to shiny appearance nalleability ductility paramagnetism 72 / 80 Category: CHEMISTRY PAST QUESTIONS The gas evolved when dilute tetraoxosulphate (VI) acid reacts with sodium hydrogen trioxocarbonate (IV) is sulphur (VI) oxide oxygen hydrogen carbon (IV) oxide 73 / 80 Category: CHEMISTRY PAST QUESTIONS 30cm3 pf hydrogen at s.t.p combine with 20cm3 of oxygen to form steam according to the following equation 2H2(g) + O2(g) → 2H2O(g). Calculate the total volume of the gaseous mixture at the end of the reaction 25cm cube 35cm cube 30cm cube 50cm cube 74 / 80 Category: CHEMISTRY PAST QUESTIONS How many electrons are removed from Cr2- when it is oxidized to CrO42-? 4 0 8 2 75 / 80 Category: CHEMISTRY PAST QUESTIONS A radioactive solid is best stored under paraffin oil in a cool, dark cupboard in a box lined with lead under ultraviolet light 76 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following is not correct about oxidation number convention? The oxidation number of a/an alkali meta like sodium in its compounds is + 1 monatomic ion is equal to its charge atom of a diatomic molecules is + 2 element in the free state is zero 77 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following can undergo both addition reactions and substitution reactions? Hexane Benzene Pentane Propene 78 / 80 Category: CHEMISTRY PAST QUESTIONS P Total = F1 + P2 + P 3 + .........Pn' where P Total is the pressure of a mixture of gasses. The equation above is an expression of Boyle's law Graham's law Dalton's law Gay-Lussac's Law 79 / 80 Category: CHEMISTRY PAST QUESTIONS What is oxidized in the reaction represented by the following equation? 3CU + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O Oxygen Nitrogen Hydrogen Copper 80 / 80 Category: CHEMISTRY PAST QUESTIONS Which of the following statements about ideal gases is/are correct? I. The cohesive forces between their particles are negligible ll. The have no definite volume but occupy the volume of their containers III. They are not compressible IV. Their particles collide with loss of energy l and ll only l, ll, lll, and IV l only l, ll and lll only Your score is 0% Restart quiz Practice also: SS 3 BIOLOGY PAST QUESTIONS (WAEC/NECO) SS 3 AGRIC SCIENCE PAST QUESTIONS (WAEC/NECO) SS 3 COMPUTER STUDIES PAST QUESTIONS (WAEC/NECO) SS 3 COMMERCE PAST QUESTIONS (WAEC/NECO) SS 3 DATA PROCESSING PAST QUESTIONS (WAEC/NECO)