NECO SSCE - Chemistry - 2003 (Objective)

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Question 5 Report

In the reaction 2H₂S(g) + SO₂(g) → 2H₂SO(I)+3S(s)SO₂is acting as _agent

a bleaching

a dehydrating

an oxidizing

a precipitating

a reducing

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

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 6 Report

What mass of silver is deposited when a current of 2.6 A is passed through a solution of a silver salt for 40 minutes? [Ag= 108 ; F=96500C]

6.89g

6.93g

6.98g

7.04g

7.12g

Answer Details

Read lesson note on Chemical Kinetics And Equilibrium System (Nigeria Only) (WAEC)

Read lesson note on Electrolysis (JAMB)

Chemical Kinetics And Equilibrium System (Nigeria Only)

Electrolysis

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Question 7 Report

Chlorine displaces bromine from aqueous potassium bromide because

bromine is a liquid at room temperature

bromine is weakly acidic.

bromine has a greater atomic radius than chlorine

chlorine is a stronger oxidising agent than bromine.

the density of chlorine is less than the density of bromine.

Answer Details

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

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 8 Report

What is the concentration (in mol dm³) of a solution containing 28 g of potassium hydroxide per 100 cm³ of solution? (K=39; H=1; 0=16)

0.01

0.05

0.1

0.5

2.8

Answer Details

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

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

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Question 9 Report

Why does the treatment of cotton fabrics with dilute acids weaken the materials?

Cotton is hydrolysed completely to glucose

The fabrics are soluble in dilute acids

The molecular chains are partially broken

The molecular chain length f the fabric increases

The thread holding the fabric together Is completely destroyed.

Answer Details

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

Read lesson note on Oxidation And Reduction (JAMB)

Acids, Bases And Salts

Oxidation And Reduction

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Question 10 Report

Which method is used for the purification of copper from its ore?

distillation

electrochemical

electrolysis

neutralization

reduction

Answer Details

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Question 11 Report

What is formed when starch is completely hydrolysed?

fructose

glucose

lactose

maltose

sucrose

Answer Details

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

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 12 Report

The reaction C₂H₆ → C₂H + H₂ is known as

dehydration

dehydrogenation

displacement

hydrogenation

reduction

Answer Details

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

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Question 13 Report

What change will occur during the electrolysis of brine using carbon electrodes?

Chlorine will be given off at the cathode

Oxygen gas will be given off at the anode

Sodium will be deposited at the cathode

The resulting solution, after electrolysis, will be acidic.

The volumes of hydrogen and chlorine given off during the same time are equal

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 14 Report

Which compound will give propane when it Is dehy drated by an excess of hot, concentrated tetraoxosvlphate(VI) acid?

CH₃CH₂CHO

CH₃CH₂CH2OH

CH₃CH₂COQH

CH₃CH₂0CH

CH₃CH₃OH

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Question 15 Report

B is an isotope of the element \(^{238} _{92}Ur\). The isotope B has

46 protons and 119 neutrons

92 protons and 92 neutrons

92 protons and 146 neutrons

92 protons and 238 neutrons

Answer Details

Read lesson note on Atomic Structure And Bonding (JAMB)

Read lesson note on Chemical Equilibria (JAMB)

Chemical Equilibria

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Question 16 Report

An organic compound gave the following results on analysis: C = 29.3% ; H = 5.7%; Br = 65%.
What is the empirical formula of the compound? [C = 12, H = 1, Br=80]

CH₃Br

C₂H₅Br

C₃H₅Br

C₃H₇Br

C₄H₉Br

Answer Details

Read lesson note on Organic Compounds (JAMB)

Organic Compounds

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Question 17 Report

What is the IUPAC name of CH₃CCI=C(CH₃)2?

2-chloro -3 methylbut -2yne

2 -chloro -3 methylbut -2ene

2 -chloro -3 methylbutene

3- methyl -2-chlorobut -2-ene

3- methyl -2. chlorobut -2 yne

Answer Details

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

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Question 18 Report

Which metal is a constituent of both bronze and solder?

copper

lead

silver

tin

zinc

Answer Details

Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Question 19 Report

What change will occur to the equilibrium mixture
\( 2CrO^{2-}_4(aq) + 2H^+(aq) ⇔ Cr_2O^{2-}_7(aq) + H_2O(l) \) when excess sodium hydrogen solution is added?

A yellow precipitate of Cr(OH)₃ is formed

An orange precipitate of Cr(OH)₃ is formed

The colour changes from orange to yellow

The colour changes from yellow to orange

There is no visible reaction.

Answer Details

Read lesson note on Chemical Kinetics And Equilibrium Systems (Ghana Only) (WAEC)

Read lesson note on Structure Of The Atom (WAEC)

Chemical Kinetics And Equilibrium Systems (Ghana Only)

Structure Of The Atom

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Question 20 Report

An atom of element X has an electronic configuration of \( 1s^22p^33s^23p^2. \) In which group of the periodic table is X?

\( \text{0} \)

Answer Details

Read lesson note on Atomic Structure And Bonding (JAMB)

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Question 21 Report

How many Faradays of electricity are required to liberate 9g of aluminium? [Al = 27]

0.1

0.3

2.7

Answer Details

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Question 22 Report

Which element is the most electronegative?

calcium

fluorine

iodine

oxygen

sodium

Answer Details

Read lesson note on Atomic Structure And Bonding (JAMB)

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Question 23 Report

The boiling point of water is higher than the boiling point of ethanol because

the bonding in water is electrovalent (ionic) whereas the bonding in ethanol is convalent

the hydrogen bonding between water molecules is stronger than the hydrogen bonding between ethanol molecules

water has a higher lattice energy than ethanol.

water has hydrogen bonding between its molecules but ethanol has no hydrogen bonging between its molecules;

water is a better solvent than ethanol.

Answer Details

Read lesson note on Chemical Bonds (Nigeria Only) (WAEC)

Read lesson note on Energy And Energy Changes (WAEC)

Chemical Bonds (Nigeria Only)

Energy And Energy Changes

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Question 24 Report

Which is NOT a synthetic polymer?

nylon

Orion

Perspex

polystyrene

wool

Answer Details

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

Basic Biochemistry And Synthetic Polymers

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Question 25 Report

Chlorine is used in water purification because it

bleaches impurities in the water

decolorizes water

destroys bacteria

is extremely soluble in water

is pleasant tasting

Answer Details

Read lesson note on Water (JAMB)

Water

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Question 26 Report

Naturally occurring lithium consists of 90% \( ^7_3Li \text{ and 10% } ^6_3 Li. \) What is the relative atomic mass of lithium?

6.8

6.9

7.1

Answer Details

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

Read lesson note on Atomic Structure And Bonding (JAMB)

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Question 27 Report

The number of hydrogen ions in 1.0dm6.00x10³ of a 0.25 mole dm6.00x10^-3 tetraoxosulphate(Vl) acid solution is
[Avogadro constant = 6.0 x 1 0]

1.45x10²³

1.50 x l0²³

3.00x10²³

3.15x10²³

6.00x10²³

Answer Details

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

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Question 28 Report

What is the change in the oxidation number of phosphorus in the following reaction?

4P(s) + 5O₂(ag) → 2P₂O₅(s)

0 to 2

0 to 5

4 to 2

4 to 5

4 to 10

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 29 Report

At s.t.p, a mole of chlorine occupies 22.4dm³. If the temperature is changed to 35°C and the pressure to 750mHg the of the new volume will be [Cl = 35.5]

\( ^{\text{760 x 22.4 x 308}} \text{750 x 273x 35.5} dm^3 \)

\( ^{\text{760 x 22.4 x 308}} \text{750 x 273}^x dm^3 \)

\( ^{\text{750 x 22.4 x 35.5}} \text{760 x 273dm3} \)

\( ^{\text{760 x 22.4 x 35.5}} \text{750x22.3x273} \)

\( ^{\text{760 x 22.4 x 35.5}} \text{750 x 308dm3} \)

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

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Question 30 Report

Which formula is used to indicate the degree of acidity of an acid?

\( [H^+] = ^{\text{mass of acid relative}} molecular mass of acid \)

F = number of H+ = ions x molar mass of the acid

Kw = [H+][OH-]

pH = - log₁₀[H+]

pKa = -log₁₀Ka

Answer Details

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

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

Periodic Chemistry (Ghana Only)

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Question 31 Report

Which hydrocarbon does NOT exhibit structural isomerism?

C₃H₆

C₄H₆

C₄H₈

C₄H₁₀

C₅H₁₂

Answer Details

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

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Question 32 Report

A calcium atom and a calcium ion have the same

chemical properties

electric charge

electronic structure

number of electrons

number of neutrons

Answer Details

Read lesson note on Atomic Structure And Bonding (JAMB)