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