Question 0An element X has 127 neutrons and 82 electrons. Its atomic number is?A.209B.105C.45D.82E.Objective Show full explanation
Question 0When a bottle of Coca-Cola is opened, bubbles of evolve. The gas is?A.hydrogenB.carbon monoxideC.carbon dioxideD.sulphur oxideE.chlorineObjective Show full explanation
Question 0When glowing splint is inserted into the mouth of a jar containing a gas, the splint is extinguished. The gas gives a white precipitate when passing into barium hydroxide. The gas is?A.methaneB.hydrogen chlorideC.hydrogenD.nitrogenE.carbondioxideObjective Show full explanation
Question 0An example of a strong electrolyte is?A.ethyl acetateB.ethanolC.glucoseD.sodium formateE.formic acidObjective Show full explanation
Question 0The oxidation number of manganese in KMnO4 is?A.+1B.+3C.+5D.+7E.+2Objective Show full explanation
Question 0Methane is member of the homologous series called?A.alkenesB.alcoholsC.estersD.alkanesE.alkynesObjective Show full explanation
Question 0For iron to rust, there should be present?A.oxygenB.moistureC.carbondioxideD.oxygen and moistureE.oxygen, moisture and carbondioxideObjective Show full explanation
Question 0The mass number of an atom is?A.the number of electrons in the atomB.the number of protons in the nucleus of the atomC.the number of neutrons in the nucleus of the atomD.the sum of numbers of electrons and protons inthe atomE.the sum of numbers of proton and neutrons in the nucleus of the atomObjective Show full explanation
Question 0Sodium and potassium belong to the same group of the Periodic Table. This is because?A.both are metalsB.both are soft and lighter than waterC.both form cations by losing electronsD.both have identical electronic configurationE.both react with water vigorouslyObjective Show full explanation
Question 0Oxidation is the process of?A.gain of electronsB.loss of electronsC.gain of hydrogenD.loss of oxygenE.addition of an electropositive element to a substanceObjective Show full explanation
Question 0the number of atoms in one mole of a substance is equal to?A.the atomic numberB.the avogadro numberC.the gas constantD.the number of neutronsE.the number of electronsObjective Show full explanation
Question 0Which of the following statements is NOT true of electrovalent compounds?A.They are solidsB.They do not vaporized easilyC.They usually dissolve in waterD.The elements forming the compounds normally have their valency electrons in a shared stateE.They conduct electricityObjective Show full explanation
Question 0If concentrated sulphric acid is added to sugar and warmed gently, the sugar changes from white to brown and finally to a black mas of carbon. In this reaction, concentrated sulphuric acid is acting as ?A.a drying agentB.an oxidizing agentC.a dehydrated agentD.a reducing agentE.a hydrolysing agentObjective Show full explanation
Question 0In the reaction C + 2HNO3 → CO2 + NO2 + NO + H2O nitric acid is acting as?A.a reducing agentB.a nitrating agentC.an oxidizing agentD.a catalytic agentE.a neutralizing agentObjective Show full explanation
Question 0The brown coloration in nitric acid prepared in the laboratory can be removed by?A.heating the acidB.bubbling air through the acidC.cooling the acidD.adding a decolorizing agentE.adding a baseObjective Show full explanation
Question 0Which of the following processes takes place during electrolysis?A.Positive ions are discharged at the anode bby gaining sufficient electrons to become neutralB.Negative ions are dicharged at the anode by gaining suficient electrons to become neutralC.Positive ions are discharged at the anode by losing sufficient electrons to become neutralD.Negative ions are discharge at the anode by losing sufficient electrons to become neutralE.Nothing happensObjective Show full explanation
Question 0In the preparation of ammonia, which of the following is used as the drying agent?A.CaOB.CaCI2C.Conc. H2SO4D.P2O5E.H3PO4Objective Show full explanation
Question 0Which of the following can have an isomer?A.C2H4B.C4H10C.C3H8D.C2H6E.C6H6Objective Show full explanation
Question 0Allotropes are elements having?A.different physical but the same chemical propertiesB.different chemical but the same physical propertiesC.the same chemical and physical propertiesD.different atomic structureE.the same position in the periodic tableObjective Show full explanation
Question 0A polymerization reaction is one in which?A.small molecules form giant moleculesB.atoms form moleculesC.giant molecules form small moleculesD.molecules form volatile compoundsE.a molecule rearranges itselfObjective Show full explanation
Question 0Which of the following is the electronic configuration of sodium? (Atomic number of Na = 11)A.1s2 2s22p6 3s2B.1s2 2s22p6 3s2 3p1s2 2s22p6 3s1C.1s2 2s22p6 3s1D.1s2 2s22p6 3s°E.1s2 2s22p6 4s1Objective Show full explanation
Question 0In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?A.One atom of hydrogen reacts with two atoms of oxygen to give one molecule of waterB.Two atoms of hydrogen react with two atoms of oxygen to give two molecules of waterC.One molecule of oxygen reacts with one molecule of hydrogen to give two molecules of waterD.One molecule of hydrogen reaccts with two molecules of oxygen to give three molecules of waterE.One molecule of oxygen reacts with two molecules of hydrogen to give two molecules of waterObjective Show full explanation
Question 0Na2CO3 + 2HCI → 2NaCI + H2O + CO2. Using the above equation, what volume of carbondioxide, measured at s.t.p is liberated when 53g of sodium carbonate is dissolved in hydrochloric acid? (1 mole of gas occupies 22.4 dm3 at s.t.p) (Na = 23, C = 12, O = 16)A.44.8 dm3B.11.2 dm3C.100.1 dm3D.3.0 dm3E.22.4 dm3Objective Show full explanation
Question 0When sodium nitrate dissolves in water, ∆H is positive. This means that?A.the reaction is catalysedB.the reaction is completeC.the reaction is exothermicD.the reaction is endthermicE.sodium nitrate is highly soluble in waterObjective Show full explanation
Question 0If an organic compound decolorizes bromine water then the compound is?A.saturatedB.supersaturatedC.unsaturatedD.a solidE.protonatedObjective Show full explanation
Question 0When air is compressed?A.its density decreasesB.it solidifiesC.its temperature decreasesD.its temperature increasesE.its temperature remains unchangedObjective Show full explanation
Question 0Fats and oils are?A.addition products of long chain fatty acids and alkaliB.addition products of long-chain fattyy acids and glycerolC.condensation products of long-chain fatty acids and glycerolD.condensation products of formaldehyde and glycerolE.liquids at 20°CObjective Show full explanation
Question 0Which of the following statements about phosphorus is NOT correct?A.Phosphorus is a solid mineralB.Phosphorus is obtained by oxidation reaction of phosphateC.Phosphorus exists in two allotropic formsD.Both forms of phosphorus are interconvertibleE.Yellow phosporus ignites when rubbed on a rough surfaceObjective Show full explanation
Question 028.8 cm3 of nitrogen at 15°C is cooled to O°C at constant pressure, the new volume of nitrogen is?A.17.4 cm3B.14.7 cm3C.27.3 cm3D.31.7 cm3E.Objective Show full explanation
Question 0If 48,000 coulombs of electricity are required to discharge 0.5 mole of sodium from a molten sodium chloride mass, then the number of coulombs required to discharge 2 moles of lead from molten lead (ll) chloride is?A.48,000B.96,000C.192,000D.384,000E.576,000Objective Show full explanation
Question 0The following compounds are given with their corresponding boiling points. Compound Boiling Point i.................................14°C ii................................24°C iii................................0°C iv................................120°C V.................................-2°C From the above information, indicate which of the following is correct?A.All the compounds are gaseous at 20 °CB.One of the compounds is gaseous at 20 °CC.Two of the compounds are gaseous at 20 °CD.Three of the compounds are gaseous at 20 °CE.None of the compounds is gaseous at 20 °CObjective Show full explanation
Question 0The products of the reaction between dilute sulphuric acid and sodium thiosulphate crystals are?A.Na2SO4 + SO2 + O2 + H2OB.Na2SO3 + SO3 + O2 + H2OC.Na2SO4 + SO2 + S + H2OD.Na2SO4 + SO3 + S + H2OE.Na2SO4 + SO2 + H2O onlyObjective Show full explanation
Question 0Which of the following is NOT a true statement of the kinetic Theory of Gases?A.The molecules move at randomB.The size of molecules is negligble as compared with the volume of gasC.The molecular collisions are perfectly elasticD.Every molecule has the same kinetic energy at a particular temperatureE.The average kinetic energy is proportional to the absolute temperature of the gasObjective Show full explanation
Question 0The electronic configuration of elements X and Y are X = 2, 8, 6; Y = 2, 8, 7. The bond in the compound formed by X and Y is expected to be?A.ionicB.covalentC.dative covalentD.metallicE.none of the aboveObjective Show full explanation
Question 05cm3 of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C? (Na = 23, Cl = 35.5)A.5.00 mole dm3B.5.67 mole dm3C.6.00 mole dm3D.6.67 mole dm3E.7.00 mole dm3Objective Show full explanation
Question 0In the extraction of iron, which of the following reactions does NOT take place in the blast furnace?A.CO2 + C → 2COB.2Fe2O3 + 3C → 4Fe + 3CO2C.Fe2O3 + 3C → 2Fe + 3CO2D.CaCO3 → CaO + CO2E.CaO + SiO2 → CaSiO3Objective Show full explanation
Question 0Pure sulphuric acid is a liquid of 1:84 density. What volume of it would be required to prepare 250 cm3 of 2.0 M solution? (H = 1, S = 32, O = 16)A.2.00B.2.66C.3.00D.3.66E.4.00Objective Show full explanation
Question 0What mass of sodium carbonate solution is in 500 cm3 of 0.1 molar sodium carbonate solution? (Na = 23, C = 12, O = 16)A.10.6 gB.5.3 gC.500 gD.10 gE.20 gObjective Show full explanation
Question 0Which of the following compounds and elements would sublime on exposure to the atmosphere?A.IceB.SulphurC.PhosphurousD.IodineE.Potassium iodieObjective Show full explanation
Question 0When hydrogen sulphide and sulphur dioxide are each passed in turn into a solution of potassium dichromate?A.both gases change the colour of the solution from yellow to colourlessB.both gases causes sulphur to be depositedC.only hydrogen sulphide decolourizes the solutionD.only sulphur dioxide deposits sulphurE.only hydrogen sulphide deposits sulphurObjective Show full explanation
Question 0Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series?A.CopperB.IronC.LeadD.PotassiumE.ZincObjective Show full explanation
Question 0If one mole of aluminium contains 6 x 1023 atoms of aluminium, how many atoms are contained in 0.9g of aluminium? (Al = 27)A.1.0 x 1021B.6.6 x 1021C.2.0 x 1022D.1.0 x 1022E.5.4 x 1023Objective Show full explanation
Question 04g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q. Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?A.There were more aluminium atoms in Q than PB.The heat given off in retarded the reactionC.Q generated more pressure than P during the reactionD.P generated more pressure than QE.Q has a greater surface area for the reaction than PObjective Show full explanation
Question 0What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?A.All the nitrate will decompose to their respective metalsB.The nitrates of calcium and potassium will decomposes to their nitritesC.Only copper nitrate decomposes to the metalD.Only the nitrates of zinc and copper will decompose to their oxidesE.The nitrates of calcium, zinc and copper decompose to their oxidesObjective Show full explanation
Question 0The scale formation in a kinetic used for boiling water is caused by the presence in water of?A.calcium sulphateB.calcium carbonateC.calcium hydrogen carbonateD.calcium hydroxideE.magnesium sulphateObjective Show full explanation
Question 0An efflorescent compound is a substance that?A.absorbs water froom the air without dissolving in itB.is capable of giving off coloured luminosityC.gives out water to the atmosphereD.absorbs water from the air and dissolves in itE.gives out its water of crystallization on heatingObjective Show full explanation
Question 0The general formula of an alkyl halide (which represent the halide) is?A.CnH2n - 2XB.CnH2n + 1XC.CnH2n + 2XD.CnH2nXE.CnH2n - 1Objective Show full explanation
Question 0The IUPAC name forA.1-methlpentaneB.3-methylbutaneC.2-methylbutaneD.1-dimethylpropaneE.2-methylpentaneObjective Show full explanation
Question 0Which of the following represents a precipitation reaction?A.H2SO4 + NaCl \(\to\) NaHSO4 + HClB.Fe +H2SO4 \(\to\) FeSO4 + H2C.4HCl + MnO2 \(\to\) MnCl2 + 2H2O + Cl2D.Na2SO4 + pb(NO3) \(\to\) PbSO4 + 2NaNOE.CuO +2HCl \(\to\) Cl2 + H2OObjective Show full explanation