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 APPQuestions 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 QUESTIONSTwo radioactive elements Q and S have half-life periods of 10 hours and 20 hours respectively. Therefore S decays faster than Q Q emits fewer particles than S Q is twice as stable as S S is more stable than Q 2 / 80 Category: CHEMISTRY PAST QUESTIONSWhat is the shape of a molecule of CCI4? Trigonal planar Linear Tetrahedral Pyramidal 3 / 80 Category: CHEMISTRY PAST QUESTIONSElactrostatic force of attraction between sodium ion and halide ion is greatest in NaCI NaBr NaF NaI 4 / 80 Category: CHEMISTRY PAST QUESTIONSA finely divided from of a metal burns more readily in air than the rod from because the rod has smaller surface area higher molar mass different chemical properties protective oxide coating 5 / 80 Category: CHEMISTRY PAST QUESTIONSIf the solubility of KHCO3 is 0.40 mole dm-3 40.0g 100.0g 10.0g 4.0g 6 / 80 Category: CHEMISTRY PAST QUESTIONSA concentrated solution containing H+, Cu2+,OH- and CI- was electrolysed using platiunm electrodes which of the ions will be discharged at the cathods? H+ OH- Cu2+ CI- 7 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the orbitals 4s, 4p, 4d and 4f has the lowest energy? 4p 4s 4d 4f 8 / 80 Category: CHEMISTRY PAST QUESTIONSThe property of calcium chloride which makes it useful as a drying agent is that it is deliquescent a strong electrolyte a normal salt ionic 9 / 80 Category: CHEMISTRY PAST QUESTIONSPipe-borne water is usually chlorinated in order to improve the teste of the water remove the hardness in the water clear kill harmful bacteria in the water coagulate sediments in the water 10 / 80 Category: CHEMISTRY PAST QUESTIONSWhat 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] 0.040dm 3 0.896dm 3 8.62dm 3 5.82dm 3 11 / 80 Category: CHEMISTRY PAST QUESTIONSHow many electrons are removed from Cr2- when it is oxidized to CrO42-? 8 0 2 4 12 / 80 Category: CHEMISTRY PAST QUESTIONSWhat type of reaction is involved when wood shavings produce a brown gas with concentrated HNO3? Nutralization Dehydration Redox reaction Destructive distillation 13 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following non-metals reacts most readily with metals? Carbon Nitrogen Sulphur Chlorine 14 / 80 Category: CHEMISTRY PAST QUESTIONSWhat 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) Dehydrating agent Acid Bleaching agent Oxidising agent 15 / 80 Category: CHEMISTRY PAST QUESTIONSWhat 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 16 / 80 Category: CHEMISTRY PAST QUESTIONSPetrol consists mainly of alktanols polymers hydrocarbons alkanoates 17 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following properties increases down a group in the Periodic Table? Atomic radius Electronegativity Ionization energy Electon affinity 18 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following statements about ideal gases is/are correct?I. The cohesive forces between their particles are negligiblell. The have no definite volume but occupy the volume of their containersIII. They are not compressibleIV. Their particles collide with loss of energy l only l and ll only l, ll, lll, and IV l, ll and lll only 19 / 80 Category: CHEMISTRY PAST QUESTIONSAn exothermic reaction is one which involves evolution of gas as it proceeds positive change in value of enthalpy attainment of dynamic equilibrium loss of heat to the surrounding 20 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following substances decomposes when an electric current is passed through it? Glucose solution Zinc rod Tetrachlormethane Hydrochloric acid 21 / 80 Category: CHEMISTRY PAST QUESTIONSWhat is the oxidation number of nitrogen in AI(NO3)3? + 3 + 1 + 5 + 6 22 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following would dissolve in warm dilute H2SO4 without effervescence, to give a blue solution? Copper alloy Copper (ll) trioxocarbonate (IV) Copper (ll) oxide Copper turnings 23 / 80 Category: CHEMISTRY PAST QUESTIONSChlorine atom forms CI by Gaining one electron Sharing one electron Donating lone pair of electrons Losing one electron 24 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following will displace copper from a solution of copper (ll) salt? Aluminium ions Zinc ions Silver Magnesium 25 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following features of a human skeleton can be determined by carbon-dating? Race Mass Age Height 26 / 80 Category: CHEMISTRY PAST QUESTIONSA 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? At equilibrium increase in temperature favours the reverse reaction The forward reaction is exthermic Pressure has no effect on the equilibrium mixture The reaction goes to completion at equilibrium 27 / 80 Category: CHEMISTRY PAST QUESTIONSEqual volumes of CO2 cnd CO at s.t.p have the same mass density rate of diffusion number of molecules 28 / 80 Category: CHEMISTRY PAST QUESTIONSThe crystal layers in graphite are held together by van der Waals' forces hydrogen bonds covalent bonds electrostatic forces 29 / 80 Category: CHEMISTRY PAST QUESTIONSPauli Exclusion Principle is related to quantum numbers of electrons collision theory of reaction rates reversiblility of equlibrium reactions electronegativity values of elements 30 / 80 Category: CHEMISTRY PAST QUESTIONSA mixture of calcium chloride and calcium trioxocarbonate (IV) in water can be separated by evaporation sublimation distillation filtration 31 / 80 Category: CHEMISTRY PAST QUESTIONS30cm3 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 50cm cube 25cm cube 35cm cube 30cm cube 32 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following pairs of reagents recat to produce hydrogen? Copper and dilute hydrochloric acid Magnesium and dilute tetraoxosulphate (VI) acid Water and calcium dicarbide Zinc and concentrated trioxonitrate (V) acid 33 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following movements can be described as random motion? gas molecules colliding in a flask wheelbarrow being pushed car travelling on a straight line planets going round the sun 34 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following lowers the activation energy of a chemical reaction? Freezing mixture Water Reducing agent Catalyst 35 / 80 Category: CHEMISTRY PAST QUESTIONSIt can be concluded that gastric juice has pH value of 7 is a mixture contains enzymes is acidic 36 / 80 Category: CHEMISTRY PAST QUESTIONSIf an element with high electron affinity combines with another element with low ionization energy the bond formed will be mainly covalent metallic dative ionic 37 / 80 Category: CHEMISTRY PAST QUESTIONSA 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 only alpha and beta particles alpha particles and gamma rays 38 / 80 Category: CHEMISTRY PAST QUESTIONSElectrovalent compounds are characterized by high molar mass solubility in ethanol strong oxidizing ability high melting point 39 / 80 Category: CHEMISTRY PAST QUESTIONSThe gas evolved when dilute tetraoxosulphate (VI) acid reacts with sodium hydrogen trioxocarbonate (IV) is sulphur (VI) oxide carbon (IV) oxide oxygen hydrogen 40 / 80 Category: CHEMISTRY PAST QUESTIONSWhat is oxidized in the reaction represented by the following equation? 3CU + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O Oxygen Hydrogen Copper Nitrogen 41 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following increases as boiling water changes to steam? activation energy temperature of the system number of molecules degree of disorder in the system 42 / 80 Category: CHEMISTRY PAST QUESTIONSWhat is the value of x in the following equation? Cr2O72- + 14H+ + xe- → 2Cr3+ + 7H2O 8 1 12 6 43 / 80 Category: CHEMISTRY PAST QUESTIONSThe spontaneity of a chemical reaction is determined by the change in the concentration of the reactants free energy of the system pressure applied to the system temperature of the system 44 / 80 Category: CHEMISTRY PAST QUESTIONSWhat does ∆H represent in the following equation ? Cl(g) + e- → CI- (g); ∆H = - 363 kJ mol-1 Heat of atomization lonization energy Electron affinity Dissociation energy 45 / 80 Category: CHEMISTRY PAST QUESTIONSMetals are said to be malleable because they can be beaten into sheets are good conductors of electricity can be alloyed are good conductors heat 46 / 80 Category: CHEMISTRY PAST QUESTIONSThe liquid product of the destructive distillation of coal is ammoniacal liquor paraffin oil ethanol kerosene 47 / 80 Category: CHEMISTRY PAST QUESTIONSCalcium atom ionizes by gaining two protons losing two electrons gaining two electrons sharing two electrons 48 / 80 Category: CHEMISTRY PAST QUESTIONSA radioactive solid is best stored under paraffin oil in a box lined with lead in a cool, dark cupboard under ultraviolet light 49 / 80 Category: CHEMISTRY PAST QUESTIONSConsider 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 volume of the system is increased a catalysty is intoduced into the system the temperature is raised the pressure increased 50 / 80 Category: CHEMISTRY PAST QUESTIONSRusting of iron is an example of deliquescence decomposition redox reaction displacement reaction 51 / 80 Category: CHEMISTRY PAST QUESTIONS0.10 mol dm-3 NaCI conducts electricity better than 0.10 mol dm-3 CH3COOH because the solution of NaCI has a lower molar mass is neutral to litmus has a higher pH contains more ions 52 / 80 Category: CHEMISTRY PAST QUESTIONSWhen alkanols react with sodium, the ga evolved is ethyne methane hydrogen oxygen 53 / 80 Category: CHEMISTRY PAST QUESTIONSWhat is responsible for metallic bonding? Attraction between positive and negative ions transfer of electrons from one atom to another Sharing of electrons between the metal atoms Attraction between the atomic unclei and cloud of electrons 54 / 80 Category: CHEMISTRY PAST QUESTIONSWhat is the effect of using vanadium (V) oxide as catalyst in the reaction represented by the following equation? 2SO2 + O2 ⇌ 2SO3; ∆H = - xKJmol-1 Shifts equilibrium position to the right Reduces the time for attainment of equilibrium Decreases the value of ∆H Increases the collision rate of reactant particles 55 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following methods is suitable for the preparation of an insoluble salt? Action of an acid on a trioxocarbonate (IV) Action of an acid on a metal Double decomposition Neutralisation 56 / 80 Category: CHEMISTRY PAST QUESTIONSConsider the following equation: Ag+ (aq) + CI-(aq) → Ag+CI- (s) ; ∆H = _65.7 kJmol-1. From the equation, it can be deduced that direct combination is involved and the reaction is endothermic the reaction is endothermic and occurs at high temperature a solid is formed and heat is evolved activation energy is high and a catalyst is required 57 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following will produce oxygen and hydrogen during its electrolysis using platinum electrode? Glucose solution Dilute sodium chloride solution Aqueous copper (ll) tetraoxosulphate (IV) Concentrated hydrochloric acid 58 / 80 Category: CHEMISTRY PAST QUESTIONSThe atoms of four elements are represented as 20Q, 16R, 10S and 8T Which of the elements would be unreactive? S R T Q 59 / 80 Category: CHEMISTRY PAST QUESTIONSOne 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] 101 122 53 40 60 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following compounds dissolves in water to form a solution with pH below 7? Sodium trioxocarbonate (IV) Potassium hydroxide Ammonium chloride Sodium tetraoxosulphate (VI) 61 / 80 Category: CHEMISTRY PAST QUESTIONSAluminium is extracted from magnetite bauxite cryolite cassiterite 62 / 80 Category: CHEMISTRY PAST QUESTIONSIn the Periodic Table, the elements that loss electrons most readily belong to Group 1 A Group 11 A Group 111 A Group V11 A 63 / 80 Category: CHEMISTRY PAST QUESTIONSWhat 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] 0.635g 6.35g 18g 0.318g 64 / 80 Category: CHEMISTRY PAST QUESTIONSP Total = F1 + P2 + P 3 + .........Pn' where P Total is the pressure of a mixture of gasses. The equation above is an expression of Gay-Lussac's Law Boyle's law Dalton's law Graham's law 65 / 80 Category: CHEMISTRY PAST QUESTIONSThe presence of unpaired electrons in an atom of a transition metal gives rise to shiny appearance ductility nalleability paramagnetism 66 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following procedures is suitable for identifying the food colouring added to a pastry sample? Both electrodes gain electrons The blue colour of the solution fades gradually The anode increases in mass The cathode becomes coated with copper 67 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following compounds dissolves in water to give an alkaline solution? Sodium chloride Ammonium chloride Sulphur (IV) oxide Potassium oxide 68 / 80 Category: CHEMISTRY PAST QUESTIONSGiven that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible? S + Q+ → Q + S+ S + P+ → P + S + R + P+ → P + R+ Q + S+ → S + Q+ 69 / 80 Category: CHEMISTRY PAST QUESTIONSChemical equilibrium is attained when concentrations of the products are greater than those of the reactants concentrations of the reactants and products remain constant reactants stop forming the products reactants in the system are used up 70 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following occurs when a solution of CuSO4 is electrolysed using copper electrodes? Both electrodes gain electrons The anode increases in mass The cathode becomes coated with copper The blue colour of the solution fades gradually 71 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following is not correct about oxidation number convention? The oxidation number of a/an atom of a diatomic molecules is + 2 element in the free state is zero monatomic ion is equal to its charge alkali meta like sodium in its compounds is + 1 72 / 80 Category: CHEMISTRY PAST QUESTIONSGas 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 73 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following contains co-ordinate covalent bond? NH4 CH4 HCI Na+CI 74 / 80 Category: CHEMISTRY PAST QUESTIONSSubstances which absorb water from the atmosphere without dissolving in it are said to be hydrated hygroscopic insolube anhydrous 75 / 80 Category: CHEMISTRY PAST QUESTIONSThe type of chemical bond that exists between potassium and oxygen in potassium oxide is ionic covalent metallic dative 76 / 80 Category: CHEMISTRY PAST QUESTIONSExhaust fumes discharged from a smoky vehicle gradually become invisible as a result of diffusion absorption combustion emission 77 / 80 Category: CHEMISTRY PAST QUESTIONSWhich of the following can undergo both addition reactions and substitution reactions? Pentane Benzene Hexane Propene 78 / 80 Category: CHEMISTRY PAST QUESTIONSDehydration of ethanol produces propan-1,2,3-triol ethene ethanoic acid ethanal 79 / 80 Category: CHEMISTRY PAST QUESTIONSHelium is preferred to hydrogen in filling balloons because hydrogen exhibits isotopy is a component of water is inflammable is diatomic 80 / 80 Category: CHEMISTRY PAST QUESTIONSElements which belong to the same group in the Periodic Table are characterized by presence of the same number of electron shells in the respective atoms difference of 14 atomic mass units between successive members presence of the same number of outermost electrons in the respective atoms difference of +1 in the oxidation numbers of successive members 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)
