NECO SSCE - Chemistry - 2003

Oxidation And Reduction

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Pregunta 5 Informe

Which is NOT a synthetic polymer?

nylon

Orion

Perspex

polystyrene

wool

Detalles de la respuesta

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

Basic Biochemistry And Synthetic Polymers

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Pregunta 6 Informe

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

Detalles de la respuesta

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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Pregunta 7 Informe

Which metal is a constituent of both bronze and solder?

copper

lead

silver

tin

zinc

Detalles de la respuesta

Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Pregunta 8 Informe

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

Detalles de la respuesta

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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Pregunta 9 Informe

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

Detalles de la respuesta

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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Pregunta 10 Informe

Which hydrocarbon does NOT exhibit structural isomerism?

C₃H₆

C₄H₆

C₄H₈

C₄H₁₀

C₅H₁₂

Detalles de la respuesta

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

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Pregunta 11 Informe

Which statement is NOT true about the composition of starch?

It contains only the atoms of carbon, hydrogen oxygen

It is a polysaccharide

Its empirical formula is C₂H₂0.

It is made from the monomerC₆H₁₂O₆.

The hydrogen and oxygen atoms are in the ratio 2:1.

Detalles de la respuesta

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

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Pregunta 12 Informe

Which metal bromide is widely used in photography?

calcium bromide

magnesium bromide

potassium bromide

silver bromide

sodium bromide

Detalles de la respuesta

Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Pregunta 13 Informe

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.

Detalles de la respuesta

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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Pregunta 14 Informe

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

Detalles de la respuesta

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

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Pregunta 15 Informe

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

Detalles de la respuesta

Read lesson note on Atomic Structure And Bonding (JAMB)

Read lesson note on Chemical Equilibra (JAMB)

Chemical Equilibra

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Pregunta 16 Informe

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

Detalles de la respuesta

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

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Pregunta 17 Informe

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

Detalles de la respuesta

Read lesson note on Water (JAMB)

Water

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Pregunta 18 Informe

What mass of copper is deposited when 6.5g of granulated zinc reacts with excess copper(II) tetraoxosulphate(VI) solution?

The equation for the reaction is: Zn(s) + \( CuSO_4(aq)→ ZnSO_4(aq)+ Cu(s)\)[CU= 64; Zn=65]

3.2 g

3.25 g

6.4 g

6.5 g

64.0 g

Detalles de la respuesta

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

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Pregunta 19 Informe

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.

Detalles de la respuesta

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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Pregunta 20 Informe

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

Detalles de la respuesta

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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Pregunta 21 Informe

Which element is the most electronegative?

calcium

fluorine

iodine

oxygen

sodium

Detalles de la respuesta

Read lesson note on Atomic Structure And Bonding (JAMB)

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Pregunta 22 Informe

Which separation technique is routinely applied in the petroleum industry?

chromatography

distillation

evaporation

fractional crystallization

fractional distillation

Detalles de la respuesta

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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Pregunta 23 Informe

Small amounts of compounds of transition metals are sometimes added to glass during manufacture in order to make the glass

acquire certain colours

easier to melt

easier to mould

little brittle

more transparent

Detalles de la respuesta

Read lesson note on Chemical Combination (JAMB)

Chemical Combination

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Pregunta 24 Informe

Which metal is extracted from bauxite?

aluminium

calcium

copper

magnesium

tin

Detalles de la respuesta

Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Pregunta 25 Informe

A calcium atom and a calcium ion have the same

chemical properties

electric charge

electronic structure

number of electrons

number of neutrons

Detalles de la respuesta

Read lesson note on Atomic Structure And Bonding (JAMB)

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Pregunta 26 Informe

Why is tetraoxosulphate(VI) acid NOT used for making carbon dioxide from calcium carbonate? It is

a dehydrating agent

a strong acid

an oxidising agent

dibasic

forms insoluble calcium tetraoxosulphate(Vl)

Detalles de la respuesta

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

Acids, Bases And Salts

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Pregunta 27 Informe

What is the number of moles of NaHCO₃in 250cm³ of its solution if the solution contains 8.4 g of NaHCO₃ in 1 dm³ of the solution. [Na = 23, 0 = 16, C = 12, H = 1)

0.25

0.05

0.025

0.01

Detalles de la respuesta

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

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Pregunta 28 Informe

The pH of water is 7.

What is the pH of orange juice?

above 10

below 2

between 5.5 and 6.5

between 7.5 and 8.5

Detalles de la respuesta

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

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Pregunta 29 Informe

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

0.1

0.3

2.7

Detalles de la respuesta

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Pregunta 30 Informe

The reaction C₂H₆ → C₂H + H₂ is known as

dehydration

dehydrogenation

displacement

hydrogenation

reduction

Detalles de la respuesta

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

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Pregunta 31 Informe

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.

Detalles de la respuesta

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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Pregunta 32 Informe

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

distillation

electrochemical

electrolysis

neutralization

reduction

Detalles de la respuesta

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Pregunta 33 Informe

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

Detalles de la respuesta

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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Pregunta 34 Informe

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]

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

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

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

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

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

Detalles de la respuesta

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