JAMB UTME - Chemistry - 1981

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Pregunta 2 Informe

Sodium and potassium belong to the same group of the Periodic Table. This is because?

both are metals

both are soft and lighter than water

both form cations by losing electrons Respuesta correcta

both have identical electronic configuration

both react with water vigorously

Detalles de la respuesta

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Periodic Chemistry (Nigeria Only)

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Pregunta 3 Informe

When air is compressed?

its density decreases

it solidifies

its temperature decreases Respuesta correcta

its temperature increases

its temperature remains unchanged

Detalles de la respuesta

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Separation Of Mixtures And Purification Of Chemical Substances

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Pregunta 4 Informe

If 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 drying agent

an oxidizing agent

a dehydrated agent Respuesta correcta

a reducing agent

a hydrolysing agent

Detalles de la respuesta

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Acids, Bases And Salts

Oxidation And Reduction

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Pregunta 5 Informe

The products of the reaction between dilute sulphuric acid and sodium thiosulphate crystals are?

Na₂SO₄ + SO₂ + O₂ + H₂O

Na₂SO₃ + SO₃ + O₂ + H₂O

Na₂SO₄ + SO₂ + S + H₂O Respuesta correcta

Na₂SO₄ + SO₃ + S + H₂O

Na₂SO₄ + SO₂ + H₂O only

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 6 Informe

Na₂CO₃ + 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)

44.8 dm³

11.2 dm³ Respuesta correcta

100.1 dm³

3.0 dm³

22.4 dm³

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Pregunta 7 Informe

Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series?

Copper

Iron

Lead

Potassium Respuesta correcta

Zinc

Detalles de la respuesta

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Metals And Their Compounds

Non-metals And Their Compounds

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Pregunta 8 Informe

The mass number of an atom is?

the number of electrons in the atom

the number of protons in the nucleus of the atom

the number of neutrons in the nucleus of the atom

the sum of numbers of electrons and protons inthe atom

the sum of numbers of proton and neutrons in the nucleus of the atom Respuesta correcta

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Pregunta 9 Informe

Oxidation is the process of?

gain of electrons

loss of electrons Respuesta correcta

gain of hydrogen

loss of oxygen

addition of an electropositive element to a substance

Detalles de la respuesta

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Oxidation And Reduction

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Pregunta 10 Informe

If an organic compound decolorizes bromine water then the compound is?

saturated

supersaturated

unsaturated Respuesta correcta

a solid

protonated

Detalles de la respuesta

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Electrolysis

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Pregunta 11 Informe

Which of the following represents a precipitation reaction?

H₂SO₄ + NaCl \(\to\) NaHSO₄ + HCl

Fe +H₂SO₄ \(\to\) FeSO₄ + H₂

4HCl + MnO₂ \(\to\) MnCl₂ + 2H₂O + Cl₂

Na₂SO₄ + pb(NO₃) \(\to\) PbSO₄ + 2NaNO Respuesta correcta

CuO +2HCl \(\to\) Cl₂ + H₂O

Detalles de la respuesta

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Pregunta 12 Informe

The scale formation in a kinetic used for boiling water is caused by the presence in water of?

calcium sulphate

calcium carbonate

calcium hydrogen carbonate Respuesta correcta

calcium hydroxide

magnesium sulphate

Detalles de la respuesta

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Solubility Of Substances (Ghana Only)

Water

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Pregunta 13 Informe

The oxidation number of manganese in KMnO₄ is?

+7 Respuesta correcta

Detalles de la respuesta

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Oxidation And Reduction

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Pregunta 14 Informe

When 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?

methane

hydrogen chloride

hydrogen

nitrogen

carbondioxide Respuesta correcta

Detalles de la respuesta

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Pregunta 15 Informe

the number of atoms in one mole of a substance is equal to?

the atomic number

the avogadro number Respuesta correcta

the gas constant

the number of neutrons

the number of electrons

Detalles de la respuesta

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Structure Of The Atom

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Pregunta 16 Informe

In the preparation of ammonia, which of the following is used as the drying agent?

CaO Respuesta correcta

CaCI₂

Conc. H₂SO₄

P₂O₅

H₃PO₄

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 17 Informe

A polymerization reaction is one in which?

small molecules form giant molecules Respuesta correcta

atoms form molecules

giant molecules form small molecules

molecules form volatile compounds

a molecule rearranges itself

Detalles de la respuesta

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Basic Biochemistry And Synthetic Polymers

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Pregunta 18 Informe

An efflorescent compound is a substance that?

absorbs water froom the air without dissolving in it

is capable of giving off coloured luminosity

gives out water to the atmosphere Respuesta correcta

absorbs water from the air and dissolves in it

gives out its water of crystallization on heating

Detalles de la respuesta

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Pregunta 19 Informe

What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?

All the nitrate will decompose to their respective metals

The nitrates of calcium and potassium will decomposes to their nitrites

Only copper nitrate decomposes to the metal

Only the nitrates of zinc and copper will decompose to their oxides

The nitrates of calcium, zinc and copper decompose to their oxides Respuesta correcta

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 20 Informe

If one mole of aluminium contains 6 x 10²³ atoms of aluminium, how many atoms are contained in 0.9g of aluminium?
(Al = 27)

1.0 x 10²¹

6.6 x 10²¹

2.0 x 10²² Respuesta correcta

1.0 x 10²²

5.4 x 10²³

Detalles de la respuesta

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Pregunta 21 Informe

Which of the following is NOT a true statement of the kinetic Theory of Gases?

The molecules move at random

The size of molecules is negligble as compared with the volume of gas

The molecular collisions are perfectly elastic

Every molecule has the same kinetic energy at a particular temperature Respuesta correcta

The average kinetic energy is proportional to the absolute temperature of the gas

Detalles de la respuesta

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Pregunta 22 Informe

Fats and oils are?

addition products of long chain fatty acids and alkali

addition products of long-chain fattyy acids and glycerol

condensation products of long-chain fatty acids and glycerol Respuesta correcta

condensation products of formaldehyde and glycerol

liquids at 20°C

Detalles de la respuesta

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Chemistry Of Carbon Compounds (Nigeria Only)

Chemistry, Industry And The Environment

Metals And Their Compounds

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Pregunta 23 Informe

Which of the following statements is NOT true of electrovalent compounds?

They are solids

They do not vaporized easily

They usually dissolve in water

The elements forming the compounds normally have their valency electrons in a shared state Respuesta correcta

They conduct electricity

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Pregunta 24 Informe

Which of the following statements about phosphorus is NOT correct?

Phosphorus is a solid mineral

Phosphorus is obtained by oxidation reaction of phosphate

Phosphorus exists in two allotropic forms

Both forms of phosphorus are interconvertible

Yellow phosporus ignites when rubbed on a rough surface Respuesta correcta

Detalles de la respuesta

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Chemical Bonds (Nigeria Only)

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Pregunta 25 Informe

Which of the following compounds and elements would sublime on exposure to the atmosphere?

Ice

Sulphur

Phosphurous

Iodine Respuesta correcta

Potassium iodie

Detalles de la respuesta

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Non-metals And Their Compounds

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Pregunta 26 Informe

In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?

One atom of hydrogen reacts with two atoms of oxygen to give one molecule of water

Two atoms of hydrogen react with two atoms of oxygen to give two molecules of water

One molecule of oxygen reacts with one molecule of hydrogen to give two molecules of water

One molecule of hydrogen reaccts with two molecules of oxygen to give three molecules of water

One molecule of oxygen reacts with two molecules of hydrogen to give two molecules of water Respuesta correcta

Detalles de la respuesta

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Chemical Combination

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Pregunta 27 Informe

Which of the following is the electronic configuration of sodium?
(Atomic number of Na = 11)

1s² 2s²2p⁶ 3s²

1s² 2s²2p⁶ 3s² 3p1s² 2s²2p⁶ 3s¹

1s² 2s²2p⁶ 3s¹ Respuesta correcta

1s² 2s²2p⁶ 3s^°

1s² 2s²2p⁶ 4s¹

Detalles de la respuesta

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Pregunta 28 Informe

The brown coloration in nitric acid prepared in the laboratory can be removed by?

heating the acid

bubbling air through the acid Respuesta correcta

cooling the acid

adding a decolorizing agent

adding a base

Detalles de la respuesta

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Pregunta 29 Informe

The 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?

All the compounds are gaseous at 20 °C

One of the compounds is gaseous at 20 °C

Two of the compounds are gaseous at 20 °C

Three of the compounds are gaseous at 20 °C Respuesta correcta

None of the compounds is gaseous at 20 °C

Detalles de la respuesta

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Pregunta 30 Informe

What mass of sodium carbonate solution is in 500 cm³ of 0.1 molar sodium carbonate solution?

(Na = 23, C = 12, O = 16)

10.6 g

5.3 g Respuesta correcta

500 g

10 g

20 g

Detalles de la respuesta

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Pregunta 31 Informe

Methane is member of the homologous series called?

alkenes

alcohols

esters

alkanes Respuesta correcta

alkynes

Detalles de la respuesta

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Periodic Chemistry (Ghana Only)

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Pregunta 32 Informe

Which of the following can have an isomer?

C₂H₄

C₄H₁₀ Respuesta correcta

C₃H₈

C₂H₆

C₆H₆

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 33 Informe

Which of the following processes takes place during electrolysis?

Positive ions are discharged at the anode bby gaining sufficient electrons to become neutral

Negative ions are dicharged at the anode by gaining suficient electrons to become neutral

Positive ions are discharged at the anode by losing sufficient electrons to become neutral

Negative ions are discharge at the anode by losing sufficient electrons to become neutral Respuesta correcta

Nothing happens

Detalles de la respuesta

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Electrolysis

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Pregunta 34 Informe

In the reaction
C + 2HNO₃ → CO₂ + NO₂ + NO + H₂O nitric acid is acting as?

a reducing agent

a nitrating agent

an oxidizing agent Respuesta correcta

a catalytic agent

a neutralizing agent

Detalles de la respuesta

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Oxidation And Reduction

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Pregunta 35 Informe

4g 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?

There were more aluminium atoms in Q than P

The heat given off in retarded the reaction

Q generated more pressure than P during the reaction

P generated more pressure than Q

Q has a greater surface area for the reaction than P Respuesta correcta

Detalles de la respuesta

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Chemical Combination

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Pregunta 36 Informe

An example of a strong electrolyte is?

ethyl acetate

ethanol

glucose

sodium formate Respuesta correcta

formic acid

Detalles de la respuesta

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Electrolysis

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Pregunta 37 Informe

Allotropes are elements having?

different physical but the same chemical properties Respuesta correcta

different chemical but the same physical properties

the same chemical and physical properties

different atomic structure

the same position in the periodic table

Detalles de la respuesta

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Chemical Equilibria

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Pregunta 38 Informe

The general formula of an alkyl halide (which represent the halide) is?

C_nH_2n - ₂X

C_nH_2n + ₁X Respuesta correcta

C_nH_2n + ₂X

C_nH_2nX

C_nH_2n - 1

Detalles de la respuesta

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Chemistry Of Carbon Compounds (Nigeria Only)

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Pregunta 39 Informe

28.8 cm³ of nitrogen at 15°C is cooled to O°C at constant pressure, the new volume of nitrogen is?

17.4 cm³

14.7 cm³

27.3 cm³ Respuesta correcta

31.7 cm³

Detalles de la respuesta

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Pregunta 40 Informe

If 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?

48,000

96,000

192,000

384,000 Respuesta correcta

576,000

Detalles de la respuesta

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Electrolysis

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Pregunta 41 Informe

Pure 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)

2.00

2.66 Respuesta correcta

3.00

3.66

4.00

Detalles de la respuesta

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Pregunta 42 Informe

When hydrogen sulphide and sulphur dioxide are each passed in turn into a solution of potassium dichromate?

both gases change the colour of the solution from yellow to colourless

both gases causes sulphur to be deposited

only hydrogen sulphide decolourizes the solution

only sulphur dioxide deposits sulphur

only hydrogen sulphide deposits sulphur Respuesta correcta

Detalles de la respuesta

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Acids, Bases And Salts

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Pregunta 43 Informe

An element X has 127 neutrons and 82 electrons.
Its atomic number is?

209

105

82 Respuesta correcta

Detalles de la respuesta

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