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