JAMB UTME - Chemistry - 1987 | Green Bridge CBT

Pregunta 1 Informe

The solubility of Na3AsO4(H2O)12 is 38.9g per 100g H2O. What is the mass percentage of Na3AsO4 in the saturated solution?

(As = 75, Na = 23, O = 16, H = 1)

87.27%

38.9%

19.1% Respuesta correcta

13.7%

Detalles de la respuesta

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Solubility Of Substances (Ghana Only)

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Pregunta 2 Informe

The reaction between sulphur (IV) oxide and oxygen is represented by the equilibrium reaction 2SO2(g) + O2(g) ↔ 2SO3(g), ∆H = -196 kJ. What factor would influence increased production of SO3(g)?

Addition of a suitable catalyst

Increase in the temperature of the reaction

Decrease in the temperature of the reaction Respuesta correcta

Decrease in the concentration of SO2(g)

Detalles de la respuesta

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Kinetic Theory Of Matter And Gas Laws

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Pregunta 3 Informe

Use the option above to answer this question. Which is the correct set of results for tests conducted respectively on fresh lime juice and ethanol.

A Respuesta correcta

Detalles de la respuesta

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Energy And Energy Changes

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Pregunta 4 Informe

An isotope has an atomic number of 17 and a mass number of 36. Which of the following gives the correct number of neutrons and protons in an atom of the isotope?

Neutrons 53, Protons 17

Neutrons 17, Protons 36

Neutrons 19, Protons 17 Respuesta correcta

Neutrons 36, Protons 17

Detalles de la respuesta

Mass number = number of protons + number of neutrons
36 = 17 + X; X = 36 -17 = 19
19 neutrons and 17 protons

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Atomic Structure And Bonding

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Pregunta 5 Informe

Magnesium ribbon was allowed to burn inside a given gas P leaving a white solid residue Q. Addition of water to Q liberated a gas which produced dense white fumes with a drop of hydrochloric acid. The gas P was?

nitrogen Respuesta correcta

chlorine

oxygen

sulphur (IV) oxide

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Chemical Combination

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Pregunta 6 Informe

Ethanol reacts with aqueous sodium mono-oxoio date (l) to give a bright yellow solid with a characteristic smell. The product is?

trichloromethane

triodomethane Respuesta correcta

iodoethane

ethanal

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 7 Informe

An element Z, contained 90% of 168Z and 10% of Z1818 its relative atomic mass is?

16.0

16.2 Respuesta correcta

17.0

17.8

Detalles de la respuesta

Mass number of Z = 16 while that of Z is 18
90 x 16 = 14.4 10 x 18 = 1.8
100 1 100 1
it relative atomic mass = 14.4 + 1.8 = 162

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Pregunta 8 Informe

Alloys are best prepared by?

high temperature weilding of the metals

electrolysis using the major metallic component as cathode

reducing a mixture of the oxies of the elements

cooling a molten mixture of the necessary elements Respuesta correcta

Detalles de la respuesta

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Metals And Their Compounds

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Pregunta 9 Informe

The atomic numbers of two elements X and Y are 12 and 19 respectively. The bond of these two elements is?

ionic

covalent Respuesta correcta

neutral

co-ordinate

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Atomic Structure And Bonding

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Pregunta 10 Informe

The greater the different in electronegativity between bonded atoms, the?

lower the polarity of the bond

higher the polarity of the bond

weaker the bond Respuesta correcta

higher the possibility of the substance formed being a molecul

Detalles de la respuesta

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Chemical Bonds (Ghana Only)

Atomic Structure And Bonding

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Pregunta 11 Informe

In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity?

Ethanoic acid, milk or magnesia, sodium chloride, hydrochloric acid and sodium hydroxide

Ethanoic acid, hydrochloric acid, milk of magnesia, sodium chloride and sodium chloride and sodium hydroxide

Hydrochloride acid, ethanol acid, sodium chloride, milk of magnesia and sodium hydroxide Respuesta correcta

Hydrochloride acid, sodium hydroxide sodium chloride, ethanol acid, and milk of magnesia

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 12 Informe

When water drops are added to calcium carbide in a container and the gas is passed through a jet and lifted, the resultant flame is called an?

oxyethylene flame

oxyhydrocarbon flame

oxyacetylene flame Respuesta correcta

oxymethane flame

Detalles de la respuesta

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Pregunta 13 Informe

Inspite of the electronic configuration, 1s22s22p2, carbon is tetraavalent because?

the electrons in both 2s and 2p orbitals have equal energy

the electrons in both 2s and 2p orbitals are equivalent

both the 2s and 2p orbitals hybridizes Respuesta correcta

the six orbitals hybridize to four

Detalles de la respuesta

both the 2s and 2p orbitals hydrodizes

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Pregunta 14 Informe

Which of the following water samples will have the highest titre value when titrated for the Ca2+ ions using soap solution?

Permanently hard water after boiling Respuesta correcta

emporarily hard water after boiling

Rain water stored in a glass jar for two years

Permanent hard water passed through permuitit

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Water

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Pregunta 15 Informe

Which of the following compounds will give a precipitate with an aqueous ammoniacal solution of copper (l) chloride?

CH3 = CHCH3

CH3 ≡ CCH3 Respuesta correcta

HC = C-CH2CH3

CH2 = CH-CH = CH2

Detalles de la respuesta

HC = C-CH2CH3

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Periodic Chemistry (Ghana Only)

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Pregunta 16 Informe

If d represents the density of a gas and K is a constant, the rate of gaseous diffusion r is related to d by the equation?

r = k/√d Respuesta correcta

r = kd

r =k/d

r = k √d

Detalles de la respuesta

r = k /√d

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Kinetic Theory Of Matter And Gas Laws

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Pregunta 17 Informe

When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?

bubbling it through concentrated H2SO2

bubbling it through water and then passing it through calcium oxide

passing it directly through calcium oxide Respuesta correcta

passing it directly through calcium chloride

Detalles de la respuesta

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Chemical Industry And Environment

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Pregunta 18 Informe

The most volatile fraction obtained from fractional distillation of crude petroleum contains?

butane , propane and kerosene

butane , propane and petrol

ethane, methane and benzene

methane, ethane and propane Respuesta correcta

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Separation Of Mixtures And Purification Of Chemical Substances

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Pregunta 19 Informe

In which of the following pairs of element is allotropy exhibited by each element?

Phosphorus and hydrogen

Oxygen and chlorine

Sulphur and nitrogen

Oxygen and sulphur Respuesta correcta

Detalles de la respuesta

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Atomic Structure And Bonding

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Pregunta 20 Informe

Corrosion is exhibited by

iron only

electropostive metals

metals below hydrogen inthe electrochemical series

all metals Respuesta correcta

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 21 Informe

Complete oxidation of propan -1- ol gives?

propanal

propan-2-al

propan-1-one

propanoic acid Respuesta correcta

Detalles de la respuesta

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Chemistry Of Carbon Compounds (Nigeria Only)

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Pregunta 22 Informe

Use the option above to answer this question. The structure of benzoic acid is

D Respuesta correcta

Detalles de la respuesta

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Chemistry Of Carbon Compounds (Nigeria Only)

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Pregunta 23 Informe

If 24.83 cm3 of 0.15 M NaOH is titrated to its end point with 39.45 cm3 of HCl, what is the molarity of the HCl?

0.094 M Respuesta correcta

0.150 M

0.940 M

1.500 M

Detalles de la respuesta

NaOH + HCl → NaCl + H2O moles ratio = 1/1
↔ (MaVa) / Mb x 39.45 = 0.094

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Pregunta 24 Informe

Oil spillage in ponds and creeks can be cleaned up by?

burning off the oil layer

spraying with detergent Respuesta correcta

dispersal with compressed air

spraying with hot water

Detalles de la respuesta

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Environmental Pollution

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Pregunta 25 Informe

The efficiency of petrol as a fuel in high-compression internal combustion engines improves with an increase in the amount of?

branched chain alkanes Respuesta correcta

straight chain alkanes

cycloalkanes

halogenated hydrocarbons

Detalles de la respuesta

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Pregunta 26 Informe

Temp (°C)	25	35	45
Time (seconds)	72	36	18

The times taken for iodine to be liberated in the reaction between sodium thiosulphate and hydrochloric acid at various temperature are as follows. These results suggest that

for a 10o rise in temperature, rate of reaction is double Respuesta correcta

for a 10 o rise in temperature, rate of reaction is halved

time taken for iodine to appear does not depend on temperature

for a 10 o rise in temperature rate of reaction is tripled

Detalles de la respuesta

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Kinetic Theory Of Matter And Gas Laws

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Pregunta 27 Informe

A stream of air was successively passed through three tubes X, Y and Z containing a concentrated aqueous solution of KOH, red hot copper powder and fused calcium chloride respectively. What was the composition of the gas emanating from tube Z?

CO2 ad ithe inert gases

N2, CO2 and the inert gases

N2 and the inert gases Respuesta correcta

water vapour, N2 and the inert gases

Detalles de la respuesta

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Kinetic Theory Of Matter And Gas Laws

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Pregunta 28 Informe

Which of the following elements will form oxide which will dissolve both in dilute HNO3 and NaOH solutions to form salts?

Al Respuesta correcta

Detalles de la respuesta

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Non-metals And Their Compounds

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Pregunta 29 Informe

Which of the following gases can best be used for demonstrating the fountain experiment?

I) Nitrogen (ii) Ammonia (iii) Nitrogen (I) oxide

(iv) Hydrogen chloride.

ii and iii

i and iii

ii and iv Respuesta correcta

ii only

Detalles de la respuesta

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Pregunta 30 Informe

Local black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the?

acid

ester of allanoic acid

alkali Respuesta correcta

alkanol

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 31 Informe

In the purification of town water supply, alum is used principally to?

kill bacteria

control the pH of water

improve the taste of the water

coagulate small pasrticles of mud Respuesta correcta

Detalles de la respuesta

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Solubility

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Pregunta 32 Informe

The best treatment for a student who accidentally poured concentrated tetraoxosulphate (VI) acid on his skin in the laboratory is to wash the skin with?

cold water

sodium hydroxide solution Respuesta correcta

iodine solution

sodium trioxocarbonate (IV) solution

Detalles de la respuesta

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Acids, Bases And Salts (Ghana Only)

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Pregunta 33 Informe

Stainless steel is an alloy of?

Iron, carbon and silver

iron, carbon and lead