Question 0A mixture of sugar and sulphur can be separated byA.dissolution in water, evapouration and filtrationB.filtration, evaporation and dissolution in waterC.dissolution in water, filtration and evaporationD.evaporation, dissolution in water and filtrationE.Objective Show full explanation
Question 0Which of the following is a physical change?A.Freezing ice creamB.dissolving calcium in waterC.burning keroseneD.Exposing white phosphorus to airE.Objective Show full explanation
Question 0The percentage of water of crystallization in ZnSO4.7H2O is [Zn = 65, S = 32, O = 1, H = 1]A.33%B.44%C.55%D.87%E.Objective Show full explanation
Question 00.0075 mole of calcium trioxocarbonate (IV) is added to 0.015 mole of a solution of hydrochloric acid. The volume of gas evolved at s.t.p is [Molar volume of a gas at s.t.p = 22.4 dm3]A.224cm3B.168cm3C.112cm3D.100cm3E.Objective Show full explanation
Question 0A gas exerts pressure on its container becauseA.the molecules of a gas collide with the walls of the containerB.some of the molecules are moving faster than othersC.of the collisions of the molecules with each otherD.of the mass of the molecules of the gasE.Objective Show full explanation
Question 0The basic assumption in the kinetic theory of gases that the collisions of the gaseous molecules are perfectly elastic implies that theA.forces of attraction and repulsion are in equilibriumB.gaseous molecules can occupy any available spaceC.gaseous molecules will continue their motion indefinitelyD.gases can be compressedE.Objective Show full explanation
Question 0If an atom is represented as \( _{11}^{23}X \), which of the following deduction is correct?A.it contains 12 protonicB.it forms a covalent chlorideC.its atomic number is 23D.it is an alkali metalE.Objective Show full explanation
Question 0Cathode rays causes an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the raysA.are positively chargedB.are negatively chargedC.have massD.travel in straight linesE.Objective Show full explanation
Question 0Which quantum number divides shells into orbitals?A.principalB.ArzimuthalC.MagneticD.SpinE.Objective Show full explanation
Question 0The type of bonding in {Cu(NH3)4}2+ isA.coordinateB.electrovalentC.metallicD.covalentE.Objective Show full explanation
Question 0The mixture of gases used in a photographer's flash tube isA.argon and kryptonB.krypton and xenonC.helium and argonD.argon and xenonE.Objective Show full explanation
Question 0When sodium trioxocarbonate (IV) decahydrate loses its water of crystallization to the atmosphere, the process isA.deliquescenceB.efflorescenceC.hygroscopicD.effervesecenceE.Objective Show full explanation
Question 0Water can be obtained as the only product during theA.combustion of hydrocarbonsB.neutraliization of an acid by baseC.combustion of hydrogenD.electrolysis of brineE.Objective Show full explanation
Question 0If 10.5g of lead (II) trioxonitrate (V) is dissolved in 20cm3 of distilled water at 18oC, the solubility of the solute in mol dm-3 is [Pb = 207, N = 14, O = 16]A.1.60B.5.25C.16.00D.525.00E.Objective Show full explanation
Question 0For a given solute, the concentration of its saturated solution in different solvents areA.the same at the same temperatureB.different at the same temperatureC.the same at different temperatureD.constantE.Objective Show full explanation
Question 0The major source of oxides of nitrogen is from the burning ofA.coalB.woodC.fuelD.chlrofluorocarbonsE.Objective Show full explanation
Question 0The acid used in electrolysis of water is diluteA.HNO3B.CH3COOHC.H2SO4D.HClE.Objective Show full explanation
Question 0What volume of 1.5M solution of KOH would contain 0.045 molesA.67.50 cm3B.30.00 cm3C.6.75 cm3D.3.00 cm3E.Objective Show full explanation
Question 0The salt formed from a reaction between citric acid and sodium hydroxide in solution will beA.acidicB.basicC.complexD.neutralE.Objective Show full explanation
Question 0The colour changes observed when testing for reducing agents using acidified potassium heptaoxodichromate (IV) solution isA.yellow to purpleB.orange to greenC.green to orangeD.purple to yellowE.Objective Show full explanation
Question 0Which of the following metals is purified commercially by electrolysis?A.ZnB.FeC.SnD.CuE.Objective Show full explanation
Question 0What current will deposit 3.25g of zinc in 2hrs? [Zn = 65, F = 96500 mol-]A.3.25AB.2.00AC.1.34AD.0.67AE.Objective Show full explanation
Question 0C(s) + H2O(g) → H2(g) + CO2(g) ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction isA.not feasibleB.at equilibriumC.feasibleD.exothermicE.Objective Show full explanation
Question 0Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth - to - mouth to each other at room temperature. The entropy in the mixture of gases is likely toA.remain unchangeB.increaseC.decreaseD.changeE.Objective Show full explanation
Question 0In the diagram above, which of the curves represents the evolution of oxygen with time in the equation 2KClO3(s) → 2KCl(s) + 3O2(g)?A.XB.YC.ZD.RE.Objective Show full explanation
Question 0A catalyst increase the rate of a chemical reaction by providing a path thatA.raise the activiation energyB.increase the temperatureC.lowers the activation energyD.increase the concentrationE.Objective Show full explanation
Question 0CuO(s) + H2(g) ↔ Cu(s) + H2O(l) What is the effect of increasing the pressure on the equilibrium reaction above?A.The equilibrium is shifted to the leftB.The equilibrium is shifted to the rightC.There is no effectD.More H2(g) is producedE.Objective Show full explanation
Question 0The equilibrium of an endothermic reaction which proceeds with an increase in volume can be shifted in the reverse direction byA.increasing the temperature and decreasing the pressureB.increasing the pressure and increasing the temperatureC.decreasing the temperature and increasing the pressureD.decreasing the pressure and decreasing the temperatureE.Objective Show full explanation
Question 0The oxidation of ammonia in excess air producesA.NOB.N2OC.NO2D.N2O4E.Objective Show full explanation
Question 0Hydrogen sulphide gas can act asA.an oxidizing agentB.a dehydrating agentC.a bleaching agentD.a precipitating agentE.Objective Show full explanation
Question 0The gasification of coke is used for the manufacturing ofA.producer gasB.natural gasC.synthetic gasD.industrial gasE.Objective Show full explanation
Question 0The gas that is most useful in protecting humans against solar radiation isA.chlorineB.ozoneC.carbon (IV) oxideD.hydrogen sulphideE.Objective Show full explanation
Question 0Which of the following allotrope of carbon is a constituent of a lead pencil?A.GraphiteB.DiamondC.LampblackD.SootE.Objective Show full explanation
Question 0which of the following metals will show the highest metallic character?A.ZincB.CopperC.BariumD.CalciumE.Objective Show full explanation
Question 0Copper metal dissolves in concentrated trioxonitrate (V) acid with the resultant evolution ofA.CO2B.SO2C.NO2D.COE.Objective Show full explanation
Question 0The type of iron that is best suited for welding, making nails, chains and iron rods isA.pig ironB.wrought ironC.cast ironD.iron pyritesE.Objective Show full explanation
Question 0In the electrolytic extraction of aluminum, the function of the molten cryolite is toA.precipitate aluminium hdroxideB.lower the melting point of aluminium oxideC.act as a raw materialsD.act as a solventE.Objective Show full explanation
Question 0One of the products of the thermal decomposition of sodium trioxonitrate (V) isA.sodiumB.nitrogenC.sodium dioxonitrate (III)D.sodium oxideE.Objective Show full explanation
Question 0A cracking process in petroleum refining can be represented byA.heptane to hepteneB.heptane to 3-methylhexaneC.heptane to propene and butaneD.heptane to 2,3,3-trimethybutaneE.Objective Show full explanation
Question 0Which of the following molecules has two other positional isomers?A.CH3CH2BrB.CH3CHBrCH3C.CBr2F2D.CH2CHBrCH2BrE.Objective Show full explanation
Question 0Which of the following class of compounds can exist as dipolar ions in solution?A.Alkanoic acidB.Fatty acidsC.Dialkanoic acidsD.Amino acidsE.Objective Show full explanation
Question 0Lucas reagent is used to test forA.alkanesB.alkanoic acidsC.alkanolsD.aminesE.Objective Show full explanation
Question 0A compound commonly used for sterilization and preservation of specimens and food isA.ethanolB.benzeneC.etherD.ammoniaE.Objective Show full explanation
Question 0An organic compound reacted with bromine water to give a colourless solution. The compound is probably anA.alkeneB.alkanalC.alkyneD.alkanoneE.Objective Show full explanation
Question 0Which of the following hydrocarbons is mainly used as fuel?A.MethyleneB.EthyleneC.MethaneD.EthyneE.Objective Show full explanation
Question 0The molecular formula of a common organic laboratory anaesthetic isA.CHCl3B.CHI3C.CCl4D.CHF3E.Objective Show full explanation
Question 0The simplest branched-chain hydrocarbon isA.ethaneB.etheneC.propaneD.butaneE.Objective Show full explanation
Question 0Organic molecules that have the suffix-ene are unsaturated hydrocarbons that haveA.a single bondB.a double bondC.a triple bondD.an ionic bondE.Objective Show full explanation
Question 0If the relative molecular mass of an element is not a whole number, it can be deduced that the element isA.Naturally radioactiveB.abundant in natureC.a transition metalD.an isotopic mixtureE.Objective Show full explanation