JAMB UTME - Chemistry - 1979

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Question 2 Report

The solution of a sample in a tube will be identified as a chloride if it gives

a white precipitate on addition of AgNO₃ and barium chloride solutions

a white precipiate when acidified with HCI, and then AgNO₃ solution added

a white precipitate when acidified with dilute HNO₃ and then AgNO₃ solution added Correct answer

a white precipitate when acidified with dilute H₂SO₄ and then barium nitrate solution added

a pungent smell of chlorine gas when dilute HCI and MnO₂ are added

Answer Details

The solution of a sample in a tube will be identified as a chloride if it gives a white precipitate when acidified with dilute HNO3 and then AgNO3 solution is added. This is because the test is a confirmatory test for chloride ions, and the white precipitate formed is silver chloride (AgCl). Chloride ions react with silver nitrate (AgNO3) to form a white precipitate of AgCl, which is insoluble in water and dilute nitric acid.

Read lesson note on Periodic Chemistry (Ghana Only) (WAEC)

Periodic Chemistry (Ghana Only)

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Question 3 Report

Indicate which of the following statements is not true as we move from left to right along the periodic Table:

atomic number of elements increases

atomic mass of elements increases

electropositive character of elements increases Correct answer

electronegative character of elements increases

number of electrons in the outermost orbits of element increases

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Read lesson note on Periodic Chemistry (Nigeria Only) (WAEC)

Periodic Chemistry (Nigeria Only)

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Question 4 Report

Which of the following raw materials would be required from the smelting of iron ore in a blast furnace?

CaCO ₃ Correct answer

Zn(NO₃)₂

CuSO₄

AICI₃

CaSO₄

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Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Question 5 Report

The oxidation state of manganese in potassium permanganate is

+7 Correct answer

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 6 Report

Which one of these compounds will NOT give an oxygen gas on heating?

Manganese dioxide

Hydrogen peroxide

Zinc nitrate Correct answer

Sodium nitrate

Ammonium nitrate

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

Oxidation And Reduction

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Question 7 Report

A gas occupies 30.0 dm³ at S.T.P. What volume would it occupy at 91^oC and 380 mm Hg?

20. 0dm³

40.0dm³

60. 0dm³

80. 0dm³ Correct answer

100. 0dm³

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

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Question 8 Report

One of the following techniques can be used to show that chlorophyll pigment is a mixture of chemical compounds and not a single coloured compound

cystallization

hydrolysis

sublimation

filtration

chromatography Correct answer

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Read lesson note on Separation Of Mixtures And Purification Of Chemical Substances (JAMB)

Separation Of Mixtures And Purification Of Chemical Substances

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Question 9 Report

Which of the following substances are all made by the process of polymerization?

Nylon and soap

Ethanoic acid margarine and ethanol

Nylon and artificial rubber Correct answer

Soap and butane

Margarine and nylon

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Read lesson note on Basic Biochemistry And Synthetic Polymers (WAEC)

Basic Biochemistry And Synthetic Polymers

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Question 10 Report

How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80)

4. 1 g

6. 1 g

8. 1g Correct answer

16.2g

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

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Question 11 Report

Which of the following contains two amphoteric oxides?

sodium oxide, Zinc oxide , Magnesium oxide

Aluminium oxide, Calcium oxide, Zinc oxide Correct answer

Potassium oxide, Lithium oxide, Carbon monoxide

Silver oxide, Lead oxide, Sodium oxide

Sulphur dioxide, Aluminium oxide, Carbon monoxide

Answer Details

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 12 Report

The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0)

N₂O₂

NO₂ Correct answer

N₂O

N₂O₃

Answer Details

Read lesson note on Chemical Combination (JAMB)

Chemical Combination

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Question 13 Report

In the redox reaction 2Fe²⁺ + CI₂ → 2Fe ^{3 +} + 2Cl

Cl₂ is reduced because it has lost electrons

Cl₂ is reduced because its oxidation number has decreased Correct answer

Cl₂ is reduced because its molecule is change to two ions

Fe²⁺ is reduced because it has lost electrons

Fe²⁺ is reduced because it has gained electrons

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Read lesson note on Redox Reactions (WAEC)

Redox Reactions

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Question 14 Report

A piece of metal (M) is dissolved in nitric acid and the resulting solution is treated with a small quantity of sodium hydroxide to produce a white precipitate (B) which redissolves on the addition of excess alkali. The precipitate (B)when ignited in a crucible produces the oxide of the metal(m). The METAL M is

Zn Correct answer

Answer Details

Read lesson note on Chemical Combination (JAMB)

Chemical Combination

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Question 15 Report

the vapour density of a gas may be defined as

the mass of a unit volume of the gas compared to an equal volume of water vapour

the mass of a unit volume of the gas compared to an equal volume of hydrogen Correct answer

the mass of a unit volume of the gas compared to an equal volume of oxygen

the mass of a unit volume of the gas minus the vapour pressure of water

two times the relative molecular mass of the gas

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Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

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Question 16 Report

Bronze is an alloy of

copper, zinc and nickel

aluminium and copper

copper and zinc

tin and zinc

tin and copper Correct answer

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Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Question 17 Report

When carbondioxide is bubbled into limewater a white precipitate is formed. If the passage of the gas is continued, the precipitate disappears. The reason for this is

calcium carbonate is formed which on reaction dissolves

calcium hydrogen carbonate is precipitated and then dissolves

calcium carbonate is formed which on reaction with further carbondioxide forms solube calcium hydrogen carbonate Correct answer

concentration of the solution has occurred with the deposition of calcium hydroxide

the solution has become saturated and solid carbondioxide has been deposited

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Read lesson note on Periodic Chemistry (Ghana Only) (WAEC)

Periodic Chemistry (Ghana Only)

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Question 18 Report

Methanoic acid mixes with water in all proportions and has about the same boiling point as water which of the following methods would you adopt to obtain pure water from a mixture of stand, water and methanoic acid?

fractional distillation

filtration followed by distillation

neutralization with sodium hydroxide followed by distillation

esterification with ethanol followed by distillation

neutralization with sodium hydroxide followed by filtration Correct answer

Answer Details

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

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Question 19 Report

When a piece of charcoal enclosed in a cylinder containing air is ignited

the toatl volume of air is increased

the relative amount of oxygen present is increased

the relative amount of nitrogen present is decreased

the relative amount of carbondioxide present is increased Correct answer

the ratio of oxygen to nitrogen in the system is increased

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

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Question 20 Report

The IUPAC name for

2-methylbut-3-ene

2-methylbut-4-ene

3-methylbut-2-ene

3-methylbut-1-ene Correct answer

3-methylpent-1-ene

Answer Details

Read lesson note on Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

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Question 21 Report

In the manufacture of iron in the blast furnace, iron (lll) oxide is mixed with coke and limestone, and different reactions occur in the process. Which of the following statements is true with respect to these reactions?

the coke is a powerful reducing agent and easily converts the iron oxide to iron

the calcuim carbonate reacts with SiO₂ an earthly impurity in the ore, to from calcuim silicate

the coke will react with the iron produced to form steel

all the carbondioxide required in the process comes from the decomposition of the calcium carbonate

the calcium carbonate decomposes to give calcium oxide, which then forms calcium silicate with the earthly impurity Correct answer

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

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Question 22 Report

Which of the structural formal above is ethanoic acid is

E Correct answer

Answer Details

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 23 Report

Two metallic ions associated with hard water are

copper and zinc

magnesium and silver

calcium and magnesium Correct answer

potassium and tin

sodium and lead

Answer Details

Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Question 24 Report

In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:
Anode Cathode

Sulphur hydrogen

Hydrogen oxygen

Oxygen Hydrogen Correct answer

Hydrogen sulphate ions

Sulphur oxygen

Answer Details

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Question 25 Report

Which of the following statements is true? When the potassium atom forms its ion

it gains one electron and becomes neutral

its atomic number decreases

it achieves electronic configuration of orgon Correct answer

it loses one proton

it loses one neutron

Answer Details

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Question 26 Report

An organic compound X has the following properties: I. It is not miscible with water. ll. lt has boiling point of 77^oC lll. lt has a sweet odour lV. lt is insoluble in sodium hydrogen carbonate solution . V lt does not decolourize bromine water X is therefore

methane

ethanoic acid

ethene

ethyl ethanoate Correct answer

carbon tetrachloride

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Question 27 Report

Which are the correct IUPAC names for H-CO₂CH₃ and CH = CH

Methyl methanoate and ethene

Metanoic acid and ethyne

Ethyl methanoate and ethyne

Methyl methanoate and ethyne Correct answer

Ethanoic acid and ethene

Answer Details

Read lesson note on Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

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Question 28 Report

On heating anhydrous iron (ll) sulphate, in addition to producing iron (iii) oxide, which of the following is produced?

SO₂ (g) + FeS (s)

SO₃ (g) +FeS(s)

SO₂ (g) + SO₃(g) Correct answer

SO₂ (g) + H₂S (g)

SO₃(g) + H₂S(g)

Answer Details

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 29 Report

Which of the following statements applies during the electroysis of sodium hydroxide sodium hydroxide solution using platinum electrodes?

Na⁺ ions are discharged at the cathode

Hydrogen ions are discharged at the anode

the concentration of sodium hydroxide decrease at both electrode compartments

the concentration of sodium hydroxide increases at the cathode only Correct answer

the concentration of sodium hydroxide increases at the anode only

Answer Details

Read lesson note on Electrolysis (JAMB)

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

Electrolysis

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Question 30 Report

When excess ethanol is heated to 145 ^oC in the presence of concentrated sulphuric acid, the product is

diethyl ether Correct answer

ethyne

diethyl sulphate

acetone

ethanoic acid

Answer Details

Read lesson note on Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

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Question 31 Report

An anhydride is

a compound wich has no water of crystallization

an oxide whose solution in water has a PH greater than 7

an oxide whose solution in water has a PH less than 7 Correct answer

an oxide that has hydrogen atoms

an amphoteric oxide

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Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 32 Report

Pick out the correct statement

Zin heated to redness reacts with steam to give oxygen and zinc oxide

Zinc heated to redness reacts with steam to give oxygen and hydrogen

Zinc does not react with hot or cold water

Zinc reacts with hot water to form zinc oxide and hydrogen Correct answer

Zinc reacts very easily with cold water to give zinc oxide and hydrogen

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Read lesson note on Atomic Structure And Bonding (JAMB)

Atomic Structure And Bonding

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Question 33 Report

Consider the following exothermic reaction 2SO₂(g) + O₂(g) = 2SO₃ (g) . If the temperature of the reaction is reduced from 800_oC to 500_oC, and no other change takes place, then

the reaction rate increases

concentration of SO₃ decreases

concentration of SO₃ increases Correct answer

SO₂ gas becomes unreactive

O₂ gas becomes unreactive

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

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Question 34 Report

In which of the following reactions is sulphur dioxide acting as an oxidizing agent?

SO ₂ + 2HNO₃ →H₂SO₄ + NO₂ + Heat

2SO₂ + 2H₂O + O₂→ 2H₂SO₄

SO₂ + 2H₂O + CI₂→ H₂SO₄ + 2HCI

SO₂ + 2H₂S → 3S + 2H₂O Correct answer

SO₂ + H₂O → H₂SO₃

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 35 Report

When ammonium, potassium and calcium carbonates are each separately heated

none of them will decompose

each of them will decompose to give carbondioxide and the respective oxide

ammonium carbonate and potassium carbonate will not decompose

only ammonium carbonate and the respective oxide Correct answer

ammonium carbonate will decompose to give carbondioxide, water and ammonia

Answer Details

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 36 Report

Weighed salts Y and Z were left exposed in the laboratory overnight. In the morning Y had gained weight, and Z had become liquid. What conclusion could be drawn about the nature of the two salts?

Z is efflorescent

Y and Z are efflorescent

Y and Z are deliquescent Correct answer

Y and Z are hygroscopic

Y is deliquescent

Answer Details

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

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Question 37 Report

Hydrogenation may be effected by

the removal of hydrogen from an alkane in the presence of a catalyst

the addition of hydrogen to an alkane in the presence of a catalyst

the addition of hydrogen to an alkyne Correct answer

the removal of hydrogen from an alkyne

the addition of hydrogen to an ethyl alcohol

Answer Details

Read lesson note on Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)