CSEC Chemistry Practice Exam 1

Paper 1 · Multiple choice · 60 questions

1. 1.The melting and boiling points of four substances are given. Substance W: melting point -210 °C, boiling point -196 °C; Substance X: melting point 1083 °C, boiling point 2567 °C; Substance Y: melting point -7 °C, boiling point 59 °C; Substance Z: melting point 114 °C, boiling point 184 °C. Which substance(s) would have particles that are far apart and moving rapidly at a room temperature of 30 °C?
   AW onlyBY onlyCW and Y onlyDX and Z only
2. 2.The melting and boiling points of four substances are given. Substance W: melting point -210 °C, boiling point -196 °C; Substance X: melting point 1083 °C, boiling point 2567 °C; Substance Y: melting point -7 °C, boiling point 59 °C; Substance Z: melting point 114 °C, boiling point 184 °C. Which substance(s) would be solid at a room temperature of 30 °C?
   AW onlyBY onlyCW and Y onlyDX and Z only
3. 3.At a sugar factory in Guyana, lime (calcium hydroxide) is added to the raw cane juice early in the process. The MAIN reason for this is to
   Amake the juice more acidic so that sucrose crystallises fasterBact as a catalyst for the conversion of sucrose to glucoseCneutralise the acids in the juice so that sucrose is not broken down and impurities settle outDbleach the juice so that white sugar is produced
4. 4.A student adds excess zinc oxide to dilute sulfuric acid. Which method is BEST for obtaining a clean sample of the unreacted zinc oxide from the mixture?
   AFiltering, then washing the residue with distilled water and drying itBEvaporating the mixture to drynessCSimple distillation of the mixtureDFractional distillation of the mixture
5. 5.Which of the following halogens exists as a solid at room temperature?
   AFluorineBChlorineCBromineDIodine
6. 6.Which of the following substances is made up of a giant lattice of ions rather than simple molecules?
   AMethaneBMagnesium oxideCWaterDCarbon dioxide
7. 7.Which of the following salts are soluble in water?
   AI. Calcium carbonateBII. Potassium sulfateCIII. Copper(II) nitrateDI and II onlyEI and III onlyFII and III onlyGI, II and III
8. 8.Which of the following is the correct ionic equation for the reaction between magnesium and dilute hydrochloric acid?
   AMg(s) + 2H⁺(aq) → Mg²⁺(aq) + H₂(g)BMg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)CMg(s) + 2H⁺(aq) + 2Cl⁻(aq) → Mg²⁺(aq) + 2Cl⁻(aq) + H₂(g)DMg(s) + H⁺(aq) → Mg²⁺(aq) + H₂(g)
9. 9.In which of the following compounds does chromium have an oxidation number of +6?
   ACrCl₂BCr₂O₃CK₂Cr₂O₇DCrO₂
10. 10.A white solid is warmed with aqueous sodium hydroxide. A gas with a sharp, choking smell is given off and it turns damp red litmus paper blue. The gas given off is
    Ahydrogen chlorideBsulfur dioxideCammoniaDchlorine
11. 11.A white solid is warmed with aqueous sodium hydroxide. A gas with a sharp, choking smell is given off and it turns damp red litmus paper blue. In this reaction, the hydroxide ions from the sodium hydroxide
    Aact as an acid by donating H⁺ ions to the solidBact as a catalyst and remain unchangedCact as an oxidising agent by gaining electronsDact as a base by accepting H⁺ ions from the solid
12. 12.A white solid is warmed with aqueous sodium hydroxide. A gas with a sharp, choking smell is given off and it turns damp red litmus paper blue. The white solid is MOST likely
    Asodium sulfateBammonium sulfateCcalcium chlorideDcopper(II) carbonate
13. 13.Which of the following can act as oxidising agents?
    AI. Sodium atomsBII. Chlorine moleculesCIII. Iron(III) ionsDI onlyEII onlyFI and III onlyGII and III only
14. 14.Concentrated sodium chloride solution is electrolysed using carbon electrodes. Which substance is formed at the cathode?
    ASodiumBChlorineCHydrogenDOxygen
15. 15.Which of the following will NOT conduct electricity?
    ASolid potassium bromideBSolid magnesiumCMolten potassium bromideDAqueous potassium bromide
16. 16.Which of the following statements about uses of isotopes is NOT true?
    ACarbon-14 is used to estimate the age of ancient wooden objects.BCobalt-60 is used in radiotherapy to treat some cancers.CUranium-235 undergoes fission to release energy in nuclear power stations.DHydrogen-1 is used as a medical tracer because it is highly radioactive.
17. 17.Which of the following properties INCREASE going down Group VII from fluorine to iodine?
    AI. Atomic radiusBII. Boiling pointCIII. Reactivity as an oxidising agentDI onlyEI and II onlyFII and III onlyGI, II and III
18. 18.A graphite pencil leaves a dark mark when it is rubbed on paper. This is MAINLY because graphite
    Ahas delocalised electrons that conduct electricityBhas a very high melting pointChas layers of atoms held by weak forces, so layers slide off easilyDis made of carbon atoms each joined to four others
19. 19.Which of the following zinc compounds is LEAST suitable for preparing zinc sulfate by reaction with dilute sulfuric acid?
    AZinc nitrateBZinc metalCZinc oxideDZinc carbonate
20. 20.Oxygen (O₂) and ozone (O₃) are allotropes of oxygen. Which of the following statements about them are correct?
    AI. Both are made up of oxygen atoms only.BII. Both have the same relative molecular mass.CIII. They have different physical properties.DI and II onlyEI and III onlyFII and III onlyGI, II and III
21. 21.Which of the following bonds can be formed by a chlorine atom?
    AI. An ionic bond by gaining one electronBII. An ionic bond by losing seven electronsCIII. A covalent bond by sharing a pair of electronsDI and II onlyEI and III onlyFII and III onlyGI, II and III
22. 22.An energy profile for a reaction shows the reactants at 150 kJ mol⁻¹, the top of the energy barrier at 210 kJ mol⁻¹ and the products at 40 kJ mol⁻¹. What is the activation energy for the forward reaction?
    A40 kJ mol⁻¹B60 kJ mol⁻¹C110 kJ mol⁻¹D170 kJ mol⁻¹
23. 23.An energy profile for a reaction shows the reactants at 150 kJ mol⁻¹, the top of the energy barrier at 210 kJ mol⁻¹ and the products at 40 kJ mol⁻¹. What is the enthalpy change, ΔH, for the forward reaction?
    A-110 kJ mol⁻¹B-60 kJ mol⁻¹C+110 kJ mol⁻¹D+170 kJ mol⁻¹
24. 24.An energy profile for a reaction shows the reactants at 150 kJ mol⁻¹, the top of the energy barrier at 210 kJ mol⁻¹ and the products at 40 kJ mol⁻¹. Which of the following statements about this reaction is NOT true?
    AΔH for the forward reaction is negative.BThe products have more energy than the reactants.CThe forward reaction gives out heat to the surroundings.DThe activation energy for the reverse reaction is 170 kJ mol⁻¹.
25. 25.Which of the following BEST describes the bonding in a nitrogen molecule, N₂?
    AOne shared pair of electrons between the atoms, with three lone pairs on each atomBTwo shared pairs of electrons between the atoms, with two lone pairs on each atomCTransfer of three electrons from one nitrogen atom to the otherDThree shared pairs of electrons between the atoms, with one lone pair on each atom
26. 26.Argon (relative atomic mass 40) is placed before potassium (relative atomic mass 39) in the periodic table because argon
    Ahas a smaller relative atomic mass than potassiumBis less reactive than potassiumChas more neutrons in its nucleus than potassiumDhas fewer protons in its nucleus than potassium
27. 27.In a school laboratory in Barbados, a few granules of calcium are dropped into a beaker of distilled water. The students observe vigorous fizzing, the water becomes cloudy white and the beaker feels warm. Which test result would be expected for the gas given off?
    AIt relights a glowing splint.BIt turns limewater milky.CIt burns with a squeaky pop when a lighted splint is held to it.DIt bleaches damp blue litmus paper.
28. 28.In a school laboratory in Barbados, a few granules of calcium are dropped into a beaker of distilled water. The students observe vigorous fizzing, the water becomes cloudy white and the beaker feels warm. The water becomes cloudy white because
    Acalcium carbonate is formed and is insolubleBcalcium oxide is formed and floats on the waterCcalcium sulfate is formed and is insolubleDcalcium hydroxide is only slightly soluble in water
29. 29.In a school laboratory in Barbados, a few granules of calcium are dropped into a beaker of distilled water. The students observe vigorous fizzing, the water becomes cloudy white and the beaker feels warm. The cloudy mixture is filtered. The pH of the filtrate is MOST likely to be about
    A2B6C7D12
30. 30.In a school laboratory in Barbados, a few granules of calcium are dropped into a beaker of distilled water. The students observe vigorous fizzing, the water becomes cloudy white and the beaker feels warm. The fact that the beaker feels warm shows that
    Amore energy is absorbed breaking bonds in the reactants than is released forming bonds in the productsBmore energy is released forming bonds in the products than is absorbed breaking bonds in the reactantsCthe reaction is endothermicDthe products contain more energy than the reactants
31. 31.Which of the following volumes of acid would exactly neutralise 25.0 cm³ of 1.0 mol dm⁻³ potassium hydroxide?
    AI. 25.0 cm³ of 1.0 mol dm⁻³ hydrochloric acidBII. 12.5 cm³ of 1.0 mol dm⁻³ sulfuric acidCIII. 50.0 cm³ of 1.0 mol dm⁻³ nitric acidDI onlyEII onlyFI and II onlyGII and III only
32. 32.Sodium hydrogencarbonate (baking soda) is sold in many Caribbean supermarkets. Which of the following statements about its uses are true?
    AI. It is used as a raising agent in baking.BII. It is used as an antacid to relieve indigestion.CIII. It is used to make plaster casts for broken bones.DI onlyEI and II onlyFII and III onlyGI, II and III
33. 33.Vinegar is a key ingredient in many bottles of Bajan pepper sauce. Which acid is present in vinegar?
    ACitric acidBLactic acidCMethanoic acidDEthanoic acid
34. 34.Which of the following lists the oxides correctly in the order basic oxide, acidic oxide, neutral oxide?
    ACalcium oxide, sulfur trioxide, nitrogen monoxideBCalcium oxide, carbon monoxide, carbon dioxideCSulfur trioxide, calcium oxide, waterDMagnesium oxide, aluminium oxide, carbon monoxide
35. 35.Which of the following is the main constituent of the natural gas produced off the coast of Trinidad?
    AEtheneBBitumenCMethaneDKerosene
36. 36.Which of the following is left as the residue at the bottom of the fractionating column when crude oil is distilled, and is used for paving roads?
    ABitumenBEtheneCMethaneDKerosene
37. 37.Which of the following hydrocarbons needs exactly 3 moles of oxygen for the complete combustion of 1 mole?
    AMethane, CH₄BEthene, C₂H₄CEthane, C₂H₆DPropene, C₃H₆
38. 38.Which of the following is used as the monomer for making the plastic poly(ethene)?
    AMethaneBBitumenCEtheneDKerosene
39. 39.An organic compound Q has a relative molecular mass between 50 and 60. When it is shaken with bromine water, the orange colour disappears quickly. Q could be
    AC₄H₁₀BC₂H₄CC₂H₅COOHDC₄H₈
40. 40.Ethanol made from sugar cane is blended with gasoline for use as a motor fuel. Ethanol is suitable as a fuel MAINLY because it
    Aabsorbs heat energy when it burnsBis easily converted to etheneCdoes not react with oxygenDreleases a large amount of heat energy when it burns
41. 41.Ethene undergoes addition reactions but ethane does not. This is because
    Aethene contains a carbon to carbon double bond that can open upBethane contains a carbon to carbon double bondCethene contains only single carbon to carbon bondsDethane is much more reactive than ethene
42. 42.Compound K is produced industrially by reacting ethene with steam over a catalyst. It is also produced when yeast ferments the sugars in molasses at Jamaican rum distilleries. K is
    Aethanoic acidBethanolCethaneDcarbon dioxide
43. 43.What is the name of the ester with the structural formula CH₃CH₂COOCH₂CH₃?
    AEthyl propanoateBPropyl ethanoateCEthyl ethanoateDPropyl propanoate
44. 44.Nylon and proteins are both condensation polymers. Which linkage do they BOTH contain?
    AEster linkageBGlycosidic linkageCCarbon to carbon double bondDAmide linkage
45. 45.Which of the following equations represents a condensation reaction?
    AC₂H₅OH + HCOOH → HCOOC₂H₅ + H₂OBC₂H₄ + H₂ → C₂H₆CCH₄ + Cl₂ → CH₃Cl + HClDC₂H₅OH + 3O₂ → 2CO₂ + 3H₂O
46. 46.Which of the following is the correct name for the compound CH₃CH(OH)CH₃?
    APropan-1-olBPropan-2-olCButan-2-olDEthanol
47. 47.When dilute hydrochloric acid is added to a solution of a metal nitrate, a white precipitate forms. The precipitate dissolves when the mixture is heated and forms again when it cools. The metal nitrate is MOST likely
    Asilver nitrateBlead(II) nitrateCzinc nitrateDcalcium nitrate
48. 48.A greenish-yellow gas with a choking smell turns damp blue litmus paper red and then bleaches it white. The gas is
    AammoniaBhydrogen chlorideCchlorineDnitrogen dioxide
49. 49.Bauxite mined in Jamaica is purified to alumina (aluminium oxide), which is then electrolysed to make aluminium. The alumina is dissolved in molten cryolite MAINLY to
    Asupply the oxygen that reacts at the anodeBprotect the steel tank from corrosionClower the operating temperature and so reduce energy costsDremove iron(III) oxide impurities
50. 50.During the electrolysis of alumina dissolved in molten cryolite, the carbon anodes must be replaced regularly because they
    Areact with the oxygen formed at them to produce carbon dioxideBare reduced by aluminium ionsCdissolve in the molten aluminiumDreact with sodium from the cryolite
51. 51.Which of the following correctly describes the cathode in the cell used to extract aluminium?
    AThe carbon lining of the steel tank, where Al³⁺ ions gain electronsBCarbon blocks dipping into the melt, where O²⁻ ions lose electronsCA copper plate, where Al³⁺ ions lose electronsDAn iron rod, where oxygen gas is released
52. 52.A white metal hydroxide, Y, dissolves in both dilute nitric acid and excess aqueous sodium hydroxide. When Y is heated strongly, it forms an oxide that is yellow while hot and white when cold. Y is MOST likely
    AAl(OH)₃BMg(OH)₂CZn(OH)₂DCa(OH)₂
53. 53.Which of the following metals is MOST electropositive?
    AIronBCopperCZincDMagnesium
54. 54.Which of the following observations would positively confirm that a gas is sulfur dioxide?
    AIt turns damp red litmus paper blue.BIt turns paper soaked in lead(II) ethanoate black.CIt relights a glowing splint.DIt turns acidified potassium manganate(VII) solution from purple to colourless.
55. 55.Groundwater in Barbados flows through coral limestone before it reaches homes. Which dissolved substance causes hardness that can be removed simply by boiling the water?
    ACalcium sulfateBCalcium hydrogencarbonateCCalcium carbonateDSodium chloride
56. 56.Which of the following displacement reactions would take place MOST readily?
    AMg(s) + ZnSO₄(aq) → MgSO₄(aq) + Zn(s)BMg(s) + CuSO₄(aq) → MgSO₄(aq) + Cu(s)CMg(s) + FeSO₄(aq) → MgSO₄(aq) + Fe(s)DMg(s) + Pb(NO₃)₂(aq) → Mg(NO₃)₂(aq) + Pb(s)
57. 57.Four methods of collecting gases are listed in the options. Which method is MOST suitable for collecting oxygen when the gas does NOT need to be dry?
    AUpward delivery: gas jar held upside down, gas enters at the top and pushes air down and outBDownward delivery: gas jar upright, gas enters at the bottom and pushes air up and outCCollection over water in an upturned gas jarDBubbling through concentrated sulfuric acid, then collecting in an upturned gas jar over the acid
58. 58.Four methods of collecting gases are listed in the options. Which method is suitable for collecting ammonia?
    AUpward delivery: gas jar held upside down, gas enters at the top and pushes air down and outBDownward delivery: gas jar upright, gas enters at the bottom and pushes air up and outCCollection over water in an upturned gas jarDBubbling through concentrated sulfuric acid, then collecting in an upturned gas jar over the acid
59. 59.Copper(II) sulfate solution is added in excess to barium chloride solution. The precipitate formed is filtered off and the filtrate is kept. What colour is the precipitate formed?
    AGreenBBlueCWhiteDYellow
60. 60.Copper(II) sulfate solution is added in excess to barium chloride solution. The precipitate formed is filtered off and the filtrate is kept. Which of the following solutions would produce a precipitate when added to the filtrate?
    AI. Silver nitrate solutionBII. Aqueous sodium hydroxideCIII. Dilute nitric acidDI and II onlyEI and III onlyFII and III onlyGI, II and III