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