JAMB UTME - Chemistry - 1984

An element that can exist in two or more different structural forms which possess the same chemical properties is said to exhibit.

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Allotropy or allotropism is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of these elements.

20 cm 3 of hydrogen gas are sparked with 20cm 3 of oxygen gas in an endimoeter at 373k (100 oC) and 1 atmosphere. The resulting mixture is cooled to 298 K (25 oC) and passed over calcium chloride. The volume of the residual gas is

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2H2 + O2 ------2H2O
2V 1V 2V
20cm3 20cm3 -------
20cm3 10cm3 20cm3
Residual gas = 20cm3 - 10cm3 of 02 = 103

The I.U.P.A.C name for the compound is

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An aqueous solution of a metal salt, M, gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia. Therefore cartion in M is

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Which of the following statements is NOT correct about all four of the acids: HBr, HNO3, H 2CO3 and H2SO4? They

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When the kerosene fraction from petrol is heated at high temperature, a lower boiling liquid is obtained. This process is known as

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Which of the following statements is INCORRECT?

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The solubility curves of four substances are shown in the figure above. Which of the four substances would crystallize from a saturated solution cooled from 353K(80oC)to 323K(50C)?

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Which of the following statements is NOT true of carbon monoxide?

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At S. T. P how many litres of hydrogen can be obtained from the reaction of 500 cm3 of 0.5 M H 2SO 4 with excess zinc metal?

(Gram molecular volume of H2 = 22. 4 dm 3)

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The name of the compound above is

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For the reaction 2Fe3+ 2I- $\to$ 2Fe2+ + I2, which of the following statements is TRUE?

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Which among the elements 1. Carbon 2. Oxygen 3. Copper 4. Bromine 5. Zinc, will NOT react with either water or steam?

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Alkanes

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An organic compound with a vapour density 56.5 has the following percentage composition:C =53.1% N = 12.4%, O = 28.3%, H = 6.2%. The molecular formula of the compound is

Relative atomic masses: N = 14, O = 16, C = 12, H = 1 )

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Alkaline hydrolysis of naturally occurring fats and oils yields

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The ratio of the number of molecules in 2g of hydrogen to that in 16g of oxygen is

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Which of the following mixtures would result in a solution of pH greater than 7?

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The diagram above (Fig.3) shows the energy profile for the reaction A + B + = C + D From this diagram, it is clear that the reaction is

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Which of the following methods may be used to prepare trioxonitrate (V) acid (nitric acid) in the laboratory?

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An example of a neutral oxide is

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The balanced equation for the reaction of tetraoxosulphate(VI)acid with aluminium hydroxide to give water and aluminium tetraoxosulphate(VI) is

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From the reactions : ZnO + Na2O $\to$ NaZnO and ZnO + CO2 $\to$ ZnCO3 it may be concluded that zinc oxide is

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In dilute solution the heat of the reaction NaOH + HCl = NaCl + H2O is - 57.3kJ. Therefore the heat of the reaction 2NaOH + H2SO4 $?$ Na2SO4 + 2H2O is

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NaOH + HCl = NaCl + H2O $\Delta$H = -57.3kJ

Heat of reaction of 2NaOH + H2O4

NaSO4 + H2O is

= 57.3 x 2 = -114.6 kJ

Water is said to be 'hard' if it

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Which of the curves shown in the figure given represents the relationships between the volume(V) and pressure(P) of an ideal gas at constant temperature?

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The function of conc. H2SO4 in the esterification of ethanoic acid with ethanol is to

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Use the diagram above to answer this question.

Which of the following represents a carboxylic acid?

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Nitrogen can best be obtained from a mixture over oxygen and nitrogen by passing the mixture over

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A molar solution of caustic soda is prepared by dissolving

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The hybridization of the carbon atom in ethyne is

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Sulphur

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Use the diagram above to answer this question.

Which of the following structural formula is NOT isomeric with the others?

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In which of the following reactions does hydrogen peroxide act as a reducing agent?

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Sodium hydroxide (NaOH) pellets are

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Which of the following electrodes is used in electrolysis of bauxite (Al2O3) in molten cryolite?

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A piece of sea shell, when dropped into a dilute solution of hydrochloric acid, produces a colourless, odourless gas which turns clear limewater milky. The sea shell contains

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Lime - water, which is used in the laboratory for the detection of carbon(iv)oxide is an aqueous solution of

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3Cl2 + 2NH3 $\to$ N2 + 6HCl. In the above reaction, ammonia acts as

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For the reaction NH4NO2 $\to$ N2 + 2H2O, calculate the volume of nitrogen that would be produced at S. T. P from 320 g of the dioxonitrate(iii)salt. (Relative atomic masses: N = 14, O = 16, H = 1)

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Sodium chloride may be obtained from brine by

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In the Haber process for the manufacture of ammonia, finely divided iron is used as

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If the cost of electricity required to deposit 1 g of magnesium is ₦5.00, how much would it cost to deposit 10g of aluminium?

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If an excess of a liquid hydrocarbon is poured into a jar of chlorine, and the sealed jar is then exposed for several hours to bring sunlight, all the chlorine gas is consumed. The hydrocarbon is said to have undergone

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Naphthalene when heated melts at 354 K (81 oC). At this temperature the molecules of naphthalene

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