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waec/wassce past questions and answers for CHEMISTRY-2023 including pdf practical

May 21 2024 01:59:00 PM

John Elijah

WAEC/GCE/NECO

WASSCE objective, essay, and practical past questions and answer (CHEMISTRY 2023)

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I warmly welcome you to Poscholars webite. First of all, I deem it fit to congratulate you in advance because we believe that for you to stumble on this post, it simply means you are ready to learn. In this post, we have compiled past questions and answers for wassce/waec 2023 Chemistry objective, the paper 2 and the paper 3(practical) have been compiled in form of pdf. I encourage you to go through this post thoroughly as it will be of immense benefit to you.
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You can study the 50 (fifty) objectives, theory and practical WASSCE physics past questions and answer for 2023 by checking the content below or using the table of content below to navigate to the number of your choice
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Table of Contents
  1. WASSCE/WAEC Chemistry (2023) Questions and Answers 1 - 10
  2. WASSCE/WAEC Chemistry (2023) Questions and Answers 11 - 20
  3. WASSCE/WAEC Chemistry (2023) Questions and Answers 21 - 30
  4. WASSCE/WAEC Chemistry (2023) Questions and Answers 31 - 40
  5. WASSCE/WAEC Chemistry (2023) Questions and Answers 41 - 50
  6. Download WASSCE/WAEC Chemistry pdF (2023) Paper 2 (essay questions and answer 1 - 5)
  7. Download WASSCE/WAEC Chemistry pdf (2023) Paper 3 (Practical questions and answer 1 - 3)
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WASSCE/WAEC Chemistry (2023) Questions and Answers 1 - 10

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1. Which of the following laws or theory cannot be explained by the application of the kinetic theory of gases?
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(a) Dalton's atomic theory
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(b) Charles' law
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(c) Gay-lussac's law
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(d) Boyle's law
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The correct answer is: (a) Dalton's atomic theory
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2. The primary component of natural gas is
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(a) Butane
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(b) Ethane
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(c) Methane
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(d) Propane
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The correct answer is: (c) Methane
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3. Thermal cracking of alkanes usually
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(a) Involves decomposition
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(b) Is an exothermic process
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(c) Produces only small alkanes
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(d) Requires hydrogen
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The correct answer is: (a) Involves decomposition
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4. Carbon is deposited in the exhaust pipes of cars because of
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(a) Contamination of petrol with diesel
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(b) Presence of carbon petrol
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(c) Presence of additives in petrol
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(d) Incomplete combustion of petrol
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The correct answer is: (d) Incomplete combustion of petrol
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5. How many moles of copper would be deposited by passing 1 Faraday of electricity through a CuCl2{CuCl}_2, solution?
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(a) 2
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(b) 1
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(c) 0.5
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(d) 0.25
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The correct answer is: (c) 0.5
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6. Alkenes can be manufactured by
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(a) Addition fo hydrogen to unsaturated vegetable oils
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(b) The cracking of hydrocarbons
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(c) Polymerization reactions
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(d) The combustion of alkanes
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The correct answer is: (b) The cracking of hydrocarbons
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7. Petrochemistry is an example of
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(a) Pure chemistry
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(b) Applied chemistry
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(c) Biochemistry
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(d) Environmental chemistry
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The correct answer is: (b) Applied chemistry
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8. Species that occur in a reaction pathway but not in the overall reaction arc known as
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(a) Products
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(b) Inhibitors
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(c) Reactants
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(d) Intermediates
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The correct answer is: (d) Intermediates
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9. Which of the following statements is correct?
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(a) An alkane with 49 carbon atoms contain 100 hydrogen atoms
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(b) Addition reactions occur between alkanes and chlorine
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(c) Butane has a lower boiling point than propane
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(d) Pentane has five isomers
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The correct answer is: (a) An alkane with 49 carbon atoms contain 100 hydrogen atoms
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10. The best indicator to use for the titratiojn of ethanoic acid with sodium hydroxide is
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(a) Methyl red
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(b) Methyl orange
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(c) Phenolphthalein
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(d) Screened methyl orange
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The correct answer is: (c) Phenolphthalein
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WASSCE/WAEC Chemistry (2023) Questions and Answers 11 - 20

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11. The reduction half equation half equation of the following reaction is:
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Zn(s)+CuSo4(aq)→ZuSo4(aq)+CU(s){Zn}_{(s)} + {CuSo}_{4(aq)} \rightarrow {ZuSo}_{4(aq)} + {CU}_{(s)}
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(a) CuSo4(s)+H2Ol→Cu(aq)2++SOaq2− {CuSo}_{4(s)} + {H}_2{O}_{l} \rightarrow {Cu}^{2+}_{(aq)} + {SO}^{2-}_{aq}
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(b) Cu(aq)2++2e−→Cus{Cu}^{2+}_{(aq)} + {2e}^{-} \rightarrow {Cu}_{s}
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(c) Cu(aq)2++e−→Cus{Cu}^{2+}_{(aq)} + {e}^{-} \rightarrow {Cu}_{s}
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(d) Zn(s)→Zn(aq)2++2e−{Zn}_{(s)} \rightarrow {Zn}^{2+}_{(aq)} + {2e}^{-}
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The correct answer is: (b) Cu(aq)2++2e−→Cus{Cu}^{2+}_{(aq)} + {2e}^{-} \rightarrow {Cu}_{s}
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12. If 100cm3{100cm}^3 of a saturated solution of sodium tetraoxosulphate (VI) at 30oC{30}^{o}C contains 10.5g of the salt, what would be its solubility at this temperature? [Na2SO4=142{Na}_{2}{SO}_{4} = 142]
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(a) 0.57moldm−30.57 mol {dm}^{-3}
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(a) 0.60moldm−30.60 mol {dm}^{-3}
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(a) 0.74moldm−30.74 mol {dm}^{-3}
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(a) 2.15moldm−32.15 mol {dm}^{-3}
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The correct answer is: (a) 0.74moldm−30.74 mol {dm}^{-3}
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13. An example of a crystalline substance that does not possess water of crystallization is
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(a) Potassium trioxonitrate
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(b) Sodium trioxocarbonate (IV)
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(c) Iron (II) Tetraoxosulphate (VI)
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(d) Sodium tetraoxosulphate (VI)
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The correct answer is: (a) Potassium trioxonitrate
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14. The salt solution formed from a reaction between ethanoic acid and sodium hydroxide solution would be
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(a) Basic
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(b) Acidic
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(c) Neutral
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(d) Amphoteric
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The correct answer is: (a) Basic
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15. Which of the following reactions represent the hydrolysis of an alkanoate?
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(a) CH3COOH+C2H5OH⇌H+CH3COOC2H5+H2O{CH}_{3}COOH + {C}_{2}H_{5}OH {\rightleftharpoons}^{H+} {CH}_3{COOC}_2{H}_{5} + {H}_{2}O
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(b) CH3COOC2H5+H2O⇌H+CH3COO−+CH3CH2OH{CH}_{3}{COOC}_2{H}_5 + {H}_{2}O {\rightleftharpoons}^{H+} {CH}_3{COO}^{-} + {CH}_{3}{CH}_{2}OH
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(c) CH3COOCH2CH3CH3+H2O⇌H+CH3COOH+CH3CH2OH{CH}_3{COOCH}_2{CH}_3{CH}_{3} + {H}_2{O} {\rightleftharpoons}^{H+} {CH}_{3}{COOH} + {CH}_3{CH}_2{OH}
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(d) CH3COOH+OH−⇌H+CH3COO−+H2O{CH}_3{COOH} + {OH}^{-} {\rightleftharpoons}^{H+} {CH}_3{COO}^{-} + {H}_2{O}
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The correct answer is: (c) CH3COOCH2CH3CH3+H2O⇌H+CH3COOH+CH3CH2OH{CH}_3{COOCH}_2{CH}_3{CH}_{3} + {H}_2{O} {\rightleftharpoons}^{H+} {CH}_{3}{COOH} + {CH}_3{CH}_2{OH}
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The correct answer is: (b) Beat
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16. Which of the following statement about the collision theory is correct?
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(a) All collisions bring about reactions
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(b) Rate of reaction is proportional to the number of effective collisions
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(c) Collision of molecules will split the molecules to react
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(d) Ineffective collision brings about chemical reaction.
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The correct answer is: (b) Rate of reaction is proportional to the number of effective collisions
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17. Why are H2SO4andCaCl2{H}_2{SO}_4 and {CaCl}_2 not suitable for drying ammonia gas? They
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(a) Are corrosive
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(b) Are poisonous
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(c) React with the gas
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(d) Pollute the gas
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The correct answer is: (c) React with the gas
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18. Which of the following equations does not illustrate correctly one of the reactions of chlorine?
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(a) H2S+Cl2→2HCl+S{H}_2{S} + {Cl}_2 \rightarrow 2HCl + S
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(b) Cl2+2NaOH→NaCl+NaClO+H2O{Cl}_2 + {2NaOH} \rightarrow NaCl + NaClO + {H}_2{O}
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(c) Cl2+2NaF→2NaCl+F2{Cl}_2 + 2NaF \rightarrow 2NaCl + {F}_2
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(d) Ca(OH)2+Cl2→CaOCl2+H2O Ca{(OH)}_2 + {Cl}_2 \rightarrow {CaOCl}_2 + {H}_2{O}
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The correct answer is: (c) Cl2+2NaF→2NaCl+F2{Cl}_2 + 2NaF \rightarrow 2NaCl + {F}_2
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19. How many unpaired electrons are present in 26Fe3+{}_{26}{Fe}^{3+}
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(a) 2
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(b) 3
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(c) 4
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(d) 5
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The correct answer is: (d) 5
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20. Going down group II in the periodic table normally
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(a) Shielding effect decreases
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(b) Melting point increases
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(c) Ionization energy increases
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(d) Electronegativity increases
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The correct answer is: None of the option is correct
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WASSCE/WAEC Chemistry (2023) Questions and Answers 21 - 30

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21. Which of the following elements has its valence electrons in the S-orbital
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(a) Sodium
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(b) Carbon
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(c) Phosphorus
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(d) Aluminium
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The correct answer is: (a) Sodium
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22. The periodic property that is used to determine whether a covalent molecule is polar or not is
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(a) Atomic radius
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(b) Electron affinity
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(c) Electronegativity
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(d) Ionization energy
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The correct answer is: (c) Electronegativity
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23. The following steps are scientific methods except
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(a) Analysis
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(b) Open-mindedness
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(c) Experimentation
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(d) Problem identification
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The correct answer is: (b) Open-mindedness
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24. Isoelectronic species have the same number of
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(a) Electrons
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(b) Neutrons
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(c) Protons
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(d) Ions
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The correct answer is: (a) Electrons
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25. An element X, has two isotopes, 3065Xand3066X{}^{65}_{30}{X} and {}^{66}_{30}{X} with relative abundance of 60% and 40% respectively. The relative atomic mass of X is
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(a) 65.00
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(b) 65.40
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(c) 65.50
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(d) 66.00
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The correct answer is: (b) 65.40
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26. The pair of compounds that belongs to the same homologous series is
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(a) C3H8andC3H6{C}_3{H}_8 and {C}_3{H}_6
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(b) C4H10andC5H10{C}_4{H}_10 and {C}_5{H}_{10}
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(c) C2H4andC4H10{C}_2{H}_4 and {C}_4{H}_{10}
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(d) C2H6andC4H10{C}_2{H}_6 and {C}_4{H}_{10}
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The correct answer is: (d) C2H6andC4H10{C}_2{H}_6 and {C}_4{H}_{10}
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27. A consequence of global warming is
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(a) Flooding
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(b) Water pollution
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(c) Air pollution
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(d) High humidity
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The correct answer is: (a) Flooding
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28. Which of the following gases has the lowest rate of diffusion? [H = 1.0, C = 12.0, N = 14.0, O = 16.0]
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(a) Nitrogen
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(b) Ammonia
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(c) Oxygen
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(d) Methane
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The correct answer is: (c) Oxygen
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29. The gas that is less dense than air is
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(a) Carbon (IV) oxide
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(b) Nitrogen
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(c) Chlorine
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(d) Oxygen
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The correct answer is: (b) Nitrogen
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30. Which of the following equimolar solutions has the highest conductivity?
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(a) H2CO3(aq){H}_2{CO}_{3(aq)}
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(b) H2SO4(aq){H}_2{SO}_{4(aq)}
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(c) NaOH(aq){NaOH}_{(aq)}
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(d) CH3COONa(aq){CH}_3{COONa}_{(aq)}
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The correct answer is: (b) H2SO4(aq){H}_2{SO}_{4(aq)}
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WASSCE/WAEC Chemistry (2023) Questions and Answers 31 - 40

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31. What takes place at the cathode during electrolysis?
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(a) Anions lose electrons
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(b) Anions are oxidized
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(c) Cations are discharged
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(d) Cations are oxidized
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The correct answer is: (c) Cations are discharged
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32. How many grammes of NaOH(s){NaOH}_{(s)} would be needed to produce 100.0cm3ofa0.20moldm3NaOH(aq){100.0cm}^{3} of a 0.20 mol {dm}^3 {NaOH}_{(aq)}? [NaOH = 40.0]
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(a) 0.02g
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(b) 0.80g
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(c) 20.0g
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(d) 800.0g
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The correct answer is: (b) 0.80g
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33. The formation of a bond between hydrogen and a highly electronegaive atom results in
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(a) Polarity
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(b) Dipole
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(c) Metallic bond
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(d) Elecrovalent bond
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The correct answer is: (a) Polarity
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34. The molecules that has a non-polar covalent bond is
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(a) H2O{H}_{2}O
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(b) HCl
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(c) NH3{NH}_{3}
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(d) Cl2{Cl}_2
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The correct answer is: Cl2{Cl}_2
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35. Which of the elements in the table below would react more readily with chlorine?
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Wassce waec which of the elements would react more readily with chlorine

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(a) W and X only
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(b) W and Z only
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(c) X and Z only
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(d) Y and Z only
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The correct answer is: (a) W and X only
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36. The relative molar mass of a gaseous hydrocarbon is 30. Determine it vapour density
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(a) 15
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(b) 30
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(c) 60
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(d) 45
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The correct answer is: (a) 15
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37. Consider the following reaction equation:
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2SO3(g)→2SO2(g)+O2(g)ΔH=+198kJmol−1{2SO}_{3(g)} \rightarrow {2SO}_{2(g)} + {O}_{2(g)} {\Delta}H = +198kJ {mol}^{-1}
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Which of the following statements about the reaction is correct?
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(a) The reaction is exothermic
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(b) The reaction container would feel warm
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(c) 198kJ of energy is given off
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(d) 198kJ of energy is absorbed
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The correct answer is: (d) 198kJ of energy is absorbed
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38. Which of the following properties does not give evidence of the kinetic theory of matter?
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(a) Evaporation
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(b) Diffusion
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(c) Polymerization
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(d) Melting
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The correct answer is: (c) Polymerization
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39. A compound that could be dried by using conc. tetraoxosulphate (VI) acid and not by calcium oxide is likely to be
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(a) An alkaline gas
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(b) A neutral salt
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(c) A deliquescent salt
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(d) An acid anhydride
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The correct answer is: (d) An acid anhydride
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**40. Positive ions in a sea of electrons are found in
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(a) Covalent bonds
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(b) Dative bonds
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(c) Ionic bonds
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(d) Metallic bonds
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The correct answer is: (d) Metallic bonds
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WASSCE/WAEC Chemistry (2023) Questions and Answers 41 - 50

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41. Dilute trioxonitrate (V) acid does not produce hydrogen when it reacts with metals because
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(a) It is a strong oxidizing agent
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(b) It reacts with the product
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(c) There is no visible reaction
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(d) It is highly corrosive
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The correct answer is: (a) It is a strong oxidizing agent
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42. How many moles are there in 3.0g of O3O_3? [O = 16]
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(a) 0.0093
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(b) 0.0930
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(c) 0.6250
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(d) 0.0625
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The correct answer is: (d) 0.0625
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43. Copper (II) ions are able to participate in co-ordinate covalent bonding because they
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(a) Are coloured
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(b) Have unpaired electrons
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(c) Have vacant d-orbital
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(d) Are positively charged
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The correct answer is: (c) Have vacant d-orbital
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44. Determine the volume of 0.100 mol of HCl in 0.250 mol dm−3{dm}^{-3} of solution
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(a) 20cm320 {cm}^3
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(b) 100cm3100 {cm}^3
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(c) 200cm3200 {cm}^3
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(d) 400cm3400 {cm}^3
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The correct answer is: (d) 400cm3400 {cm}^3
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45. Which of the statements about gases is not correct?
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(a) The total kinetic energy of the gas is not affected by collision
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(b) Molecules of the gas are in constant motion
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(c) Gases have low densities compared to solids and liquids of equal mass
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(d) Gases are highly soluble in water at high temperatures
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The correct answer is: (d) Gases are highly soluble in water at high temperatures
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46. Arrange the following compounds in decreasing order of their boiling points
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NH3,HF,SiH4,CH4{NH}_{3}, HF, {SiH}_{4}, {CH}_4
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(a) NH3,CH4,SiH4,HF{NH}_{3}, {CH}_{4}, {SiH}_{4}, HF
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(b) CH3,SiH4{CH}_{3}, {SiH}_{4}
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(c) HF,NH3,SiH4,CH4HF, {NH}_{3}, {SiH}_{4}, {CH}_{4}
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(d) CH4SiH4,HF,NH3{CH}_{4} {SiH}_{4}, HF, {NH}_3
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The correct answer is: (c) HF,NH3,SiH4,CH4HF, {NH}_{3}, {SiH}_{4}, {CH}_{4}
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47. The following statements are correct except
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(a) Energy is released when liquids change to solids
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(b) Particles move faster in the gaseous state than in the liquid state
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(c) Carbon atoms in gaseous methane are further apart than those in solid diamond
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(d) There is large decrease in the volume of a solid metal when pressure is applied to it
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The correct answer is: (d) There is large decrease in the volume of a solid metal when pressure is applied to it
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48. The vapour density of an organic compound with the molecular formula C4H4O2{C}_4{H}_4{O}_2 is [H = 1.0, C = 12.0, O = 16.0]
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(a) 120
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(b) 65
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(c) 40
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(d) 30
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The correct answer is: (d) 30
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49. A mixture containing two salts of different solubility can be separated by
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(a) Chromatography
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(b) Distillation
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(c) Crystallization
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(d) Evaporation
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The correct answer is: (c) Crystallization
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50. The separation technique that is suitable for separating iodine from tetrachloromethane is
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(a) Solvent extraction
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(b) Fractional distillation
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(c) Decantation
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(d) Filtration
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The correct answer is: (a) Solvent extraction
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Download WASSCE/WAEC Chemistry pdF (2023) Paper 2 (essay questions and answer 1 - 5)

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We have provided a pdf where you can practice wassce Paper 2 (essay questions) for Chemistry 2023. To download the pdf right away,
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Download WASSCE/WAEC Chemistry pdf (2023) Paper 3 (Practical questions and answer 1 - 3)

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We have also provided a pdf where you can practice wassce Paper 3 (practical) for Chemistry 2023. To download the pdf right away,
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Without doubt I believe you are happy with the questions and answers on WASSCE/WAEC Chemistry 2023 you saw above. We have compiled this to ensure students have access to resources that can help them blast their WASSCE exam. If you have any comment or you observe any flaw do well to leave a comment in the comment-box below and we will get back to you
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I recommend you check my article on the following:
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- WASSCE/WAEC past questions and answers for CHEMISTRY-2022
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This is all we can take on “WASSCE objective, essay, and practical past questions and answer for (CHEMISTRY 2023)“.
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