*JAMB CHEMISTRY PRACTICAL QUESTIONS AND ANSWERS 📝📚🧠🔥🔥* 1)The knowledge of half-life can be used to A. Create an element B. Detect an element C. to combine elements D. Irradiate an element 2)An element X forms the following compounds with chlorine; XCl4, XCl3, XCl2. This illustrates the A. law of multiple proportions B. law of chemical proportions C. law of simple proportions D. law of conservation of mass 3)The hydrogen ion concentration of a sample of orange juice is 2.0 X 10−11 moldm−3. What is its pOH? [log102 = 0.3010] A. 3.30 B. 13.00 C. 10.70 D. 11.30 4)2SO2 (g)+ O2 (g) ↔ 2SO3(g) ΔH = -395.7kJmol−1 In the equation, an increase in temperature will shift the equilibrium position to the A. left and equilibrium constant decreases B. left and equilibrium constant increases C. right and equilibrium constant increases D. right and equilibrium constant decreases 5)The end products of burning a candle in the atmosphere are water and A. carbon (II) oxide B. sulphur (IV) oxide C. carbon (IV) oxide D. sulphur (VI) oxide 6) The collision theory explains reaction rates in terms of A. size of the product B. frequency of collision of the reactants C. size of reactant D. frequency of collision of the products 7)The presence of ammonia gas in a desiccator can exclusively be removed by A. phosphorus (V) oxide B. fused calcium chloride C. calcium oxide D. concentrated tetraoxosulphate (VI) acid 8)Aluminium does not react with either dilute or concentrated trioxonitrate (V) acid because A. it is insoluble in either dilute or concentrated trioxonitrate (V) acid B. it is lower than hydrogen in the electrochemical series C. the reaction with trioxonitrate (V) acid has a light activation energy D. an insoluble oxide is formed on its surface which renders it passive 9)Which of these sources of water may likely contain the least concentration of Ca2+ and Mg2+? A. Spring water B. River water C. Tap water D. Sea water 10)The conductivity of an acid solution depends on the A. amount of ions present and their mobilities B. mobilities of the ions present C. amount of ions present D. temperature of the solution 11)Which of the following metals cannot replace hydrogen from water or steam? A. Sodium B. Magnesium C. Iron D. Copper 12)Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore, A. P will form an electrovalent bond with R B. Q will form a covalent bond with S C. R will form an electrovalent bond with S D. Q will form an electrovalent bond with S 13)During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment A. the litmus turns blue but no gas is evolved B. the litmus turns blue and oxygen is evolved C. the litmus turns blue and hydrogen is evolved D. the litmus turns red and oxygen is evolved 14)The derivative of benzene that can be used in making explosives is A. aniline B. xylene C. phenol D. toluene 15)In electrovalency, the oxidation number of the participating metal is always A. decreasing B. increasing C. constant D. neutral 16)The ionic radii of metals are usuall A. greater than their atomic radii B. unaffected by the charge on the ion C. the same as their atomic radii D. less than their atomic radii 17)Calculate the percentage composition of oxygen in calcium trioxocarbonate(IV) [Ca=40, C=12, O=16] A. 16 B. 48 C. 40 D. 12 18)Which of these alloys contains copper? A. solder B. steel C. permallory D. bronze 19)If the molecular mass of tetraoxosulphate (VI) acid is 98, calculate its vapour density. A. 196 B. 49 C. 106 D. 82 20)Sieving is a technique used to separate mixtures containing solid particles of A. small sizes B. large sizes C. different sizes D. the same size 21)3H2(g)+ N2(g)⇔ 2NH3(g) ; H= -ve In the reaction above, lowering of temperature will A. have no effect on the equilibrium position B. increase the rate of both the forward and reverse reactions equally C. favour the forward reaction D. favour the reverse reaction 22)The situation obtained when a perfect gas expands into a vacuum is A. ΔH is positive and TΔ S is zero B. ΔH is positive and T Δ S is negative C. ΔH is negative and TΔ S is zero D. ΔH is zero and T Δ S is positive 23)The general formula of alkanones is A. RCHO B. R2 CO C. RCOOH D. RCOOR 24)The alkanoic acid found in human sweat is A. CH3 -COOH B. CH3 —CH2 —COOH C. H-COOH D. CH3 25)The elements in the periodic table are listed in order of increasing A. relative atomic number B. atomic mass C. relative isotopic mass D. nuclear charge 26)H2 S(g)+ Cl2(g)→ 2HCl(g)+ S(g) In the reaction above, the substance that is reduced is A. H2 S B. S C. HCl D. Cl2 27)Which of the compounds is composed of Al, Si, O and H? A. Elson salt B. Limestone C. Clay D. Urea 28)When large hydrocarbon molecules are heated at high temperature in the presence of a catalyst to give smaller molecules, the process is known as A. disintegration B. polymerization C. cracking D. degradation 29)In the removal of water hardness, permutit is regenerated with a strong solution of A. NaOH B. Na3 SO4 C. Na3 CO3 D. NaCl 30)A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by A. boiling the water B. adding excess calcium hydroxide C. adding a calculated amount of calcium hydroxide D. adding sodium carbonate 31)Which of the following separation techniques can be employed in obtaining solvent from its solution? A. Evaporation B. Distillation C. Filtration D. Precipitation 32)In the upper atmosphere, the ultra-violet light breaks off a free chlorine atom from chlorofluorocarbon molecule. The effect of this is that the free chlorine atom will A. be very reactive and will attack ozone B. be non-reactive and will not attack ozone C. not change the level of ozone in the atmosphere D. increase the level of ozone in the atmosphere 33)A given amount of gas occupies 10.0dm\(^3\) at 4atm and 273°C. The number of moles of the gas present is? [Molar volume of gas at s.t.p = 22.4dm\(^3\)] A. 0.89 mol B. 1.90 mol C. 3.80 mol D. 5.70 mol 34)According to Charles' law, the volume of a gas becomes zero at A. 0°C B. -100°C C. -273°C D. -373°C 35)A substance that is used as a ripening agent for fruits is A. ethene B. propane C. methane D. butane 36)The Sulphide which is insoluble in dilute hydrochloric acid i A. FeS B. CuS C. ZnS D. Na2S 37)What is the PH of 0.00 1 moldm\(^3\) solution of the sodium hydroxide A. 14 B. 13 C. 12 D. 11 38)The type of bonding in [Cu(NH\(_3\))\(^4\)(^{2+}\) is A. coordinate B. electrovalent C. metallic D. covalent 39)Which of the following is an example of a chemical change? A. dissolution of salt in water B. rusting of iron C. melting of ice D. separating a mixture by distillation 40)To what temperature must a gas at 273k be heated in order to double both its volume and pressure? A. 298K B. 546K C. 819K D. 1092K