NECO SSCE - Chemistry - 2001 (Objective)

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Question 6 Report

An experiment to test the conductance of 0,1 M solutions of the substances listed below was perform.
I ammonia
II ammonium chloride
III ethanoic acid
IV sodium ethanoate
Which pair of substances show the least conductance?

I and II

I and III Correct answer

I and IV

II and III

II and IV

Answer Details

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

Acids, Bases And Salts

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Question 7 Report

The green colour solution of an Fe2 salt changes to a brown solution of an Fe3+ salt by

conversion.

elimination.

oxidation. Correct answer

reduction.

substitution.

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 8 Report

Which metal will dissolve in aqueous sodium hydroxide?

aluminium Correct answer

copper

iron

sikeer

tin

Answer Details

Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

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Question 9 Report

Which compound can be used as a reducing agent in a reaction?

Cl₂

KMnO₄

KCr₂O₇

MnO₂

Na₂SO₃ Correct answer

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 10 Report

The maximum number of electrons that can occupy the shell having a principal quantum number of 3 is

18 Correct answer

Answer Details

Read lesson note on Structure Of The Atom (Ghana Only) (WAEC)

Read lesson note on Atomic Structure And Bonding (JAMB)

Structure Of The Atom (Ghana Only)

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Question 11 Report

Which compound will have the lowest boiling point?

CH₃OH

CH₃COOH

CH₃CHOH

C₄H₁₀ Correct answer

(CH₃)₃CH

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

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Question 12 Report

Animal charcoal differs from wood charcoal in that it

has a dark colour

has a high carbon content

is a good absorbent

is crystalline.

is rich in phosphate content Correct answer

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Read lesson note on Solubility (JAMB)

Solubility

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Question 13 Report

The use of sulphur to vulcanize rubber is mad to make it

blacker.

cheaper. .

more elastic

tougher Correct answer

softer.

Answer Details

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

Acids, Bases And Salts

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Question 14 Report

Which of the following is TRUE of a catalyst? I. it alters the activation energy of a reaction
II. it is effective in a reaction but cannot initiate a reaction
III, it affects the equilibrium of a reversible reaction
IV. it affects the overall reaction

I and II only Correct answer

I, II and III only

II and III only

II, II and IV only

III and IV only

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

Chemical Kinetics And Equilibrium System (Nigeria Only)

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Question 15 Report

The Atomic theory model which explains that electrons in an atom revolve round quantized energy levels is attributed to

Becquerel.

Bohr. Correct answer

de Broglie.

Rutherford.

Thompson.

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Read lesson note on Atomic Structure And Bonding (JAMB)

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Question 16 Report

Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?

boiling off the ethanoic

filtration

fractional crystallisation

fractional distillation Correct answer

isomerisation

Answer Details

Read lesson note on Solubility (JAMB)

Read lesson note on Organic Compounds (JAMB)

Solubility

Organic Compounds

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Question 17 Report

Which element contains the greatest number of moles?

8 g of Helium

48 g of Carbon Correct answer

78 g of Potassium

130g of Zinc

216g of Sliver

Answer Details

Read lesson note on Metals And Their Compounds (JAMB)

Read lesson note on Chemical Combination (JAMB)

Metals And Their Compounds

Chemical Combination

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Question 18 Report

The decreasing order of the oxidising power of the halogens is

Br>I>Cl>F

F>I>Cl>Br

F>Cl>Br>l Correct answer

I>Br>Cl>F

Cl>Br>F>I

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 19 Report

Fructose and glucose are

allotropes of each other.

both disaccharides

dimere of each other.

isomers of each other Correct answer

isotopes of each other

Answer Details

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

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

Chemistry Of Carbon Compounds (Ghana Only)

Separation Of Mixtures And Purification Of Chemical Substances

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Question 20 Report

what dose the following equation illustrate? \( ^{238}U_{92} → ^{234}Th_{90} + ^4 He_2 \)

Artificial radioactivity

nuclear fission

nuclear fusion

radio-decomposition

spontaneous disintegration Correct answer

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Read lesson note on Structure Of The Atom (WAEC)

Structure Of The Atom

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Question 21 Report

To test for the presence of chloride ions in ion, correct sequence of reagents to use is

Ba(NO₃)₂(aq) then HNO₃(aq).

HCl(aq) then Ba(NO₃)₂(aq).

HCl(aq) then Ag₃(aq).

HNO₃(aq) then fresh FeSO₄(aq).

HNO₃(aq) then AgNO₃(aq). Correct answer

Answer Details

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

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

Acids, Bases And Salts

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Question 22 Report

The oxidation number of X in \(XO_{4}^{3-}\) is

-2

5 Correct answer

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 23 Report

Which statement BEST describes the process of oxidation?

addition of hydrogen

loss of oxygen

decrease in oxidation number

loss of electrons Correct answer

gain of elections.

Answer Details

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

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Question 24 Report

NaCl(s) does NOT conduct electricity, but N(aq) does. This is because

NaCl(s) is non-ionic but NaCl(aq) is ion

NaCl(aq) contains mobile electrons, where absent in NaCl(s).

NaCl(aq) contains mobile ions which Nacl,) does not contain. Correct answer

NaCl(s) ionizes partiality while NaCl(aq) iodizes completely.

NaCl(s) decomposes when heated but NCl(aq) is stable to heat. –

Answer Details

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

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Question 25 Report

A gas X diffuse through porous partition at the rate of 3 cm₃ per second. Under the same condition hydrogen diffused at the rate of 15 cm₃ per second.

What is the 42. relative molecular mass of X.

50 Correct answer

Answer Details

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

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Question 26 Report

On exposure to hydrogen sulphide, moist lead (II) ethanoate paper turns

black Correct answer

blue

green

white

yellow

Answer Details

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

Acids, Bases And Salts

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Question 27 Report

Which method is NOT used to determine rate of a reaction?

change in amount of precipitate formed

change in equilibrium constant Correct answer

change in intensity of colour

change in pH values.

change in total gas pressure

Answer Details

Read lesson note on Rates Of Chemical Reaction (JAMB)

Rates Of Chemical Reaction

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Question 28 Report

20 cm³ of 0.09 mol dm³ solution of tetraoxosuiphate (Vi) acid requires 30cm³ of sodium hydroxide solution for complete neutralization. The molar concentration of sodium hydroxide is [H = 1; S = 32; 0 = 16; Na = 23]

0.03 mol dm³

0.12 mol dm³ Correct answer

0.27 mol dm³

0.45 mol dm³

0.90 mol dm³

Answer Details

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

Acids, Bases And Salts

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Question 29 Report

What is the ratio of the rate of diffusion of carbon(IV) oxide to that of propane, under the same conditions? [H = 1; C= 12; 0= 161

1:01 Correct answer

1:02

2:01

2:03

3:01

Answer Details

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

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Question 30 Report

if an element X with atomic number 13 combines with an element Y whose atomic number is 8 the most likely formula of the compound formed between X and Y is?

X₂Y

XY₂

X₃Y₂

X₂Y₃ Correct answer

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Read lesson note on Atomic Structure And Bonding (JAMB)

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Question 31 Report

The molar mass of a compound X is 56. its empirical formula is CH2. X is

butene. Correct answer

butyne.

ethene.

propene.

propyne

Answer Details

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

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

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Chemistry Of Carbon Compounds (Nigeria Only)

Stoichiometry And Chemical Reactions

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Question 32 Report

A measure of the degree of disorderliness in a chemical system is known as the

activation energy

enthalpy

entropy Correct answer

equilibrium

free energy.

Answer Details

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

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Question 33 Report

The atomic number of iron is 56. The number of unpaired electrons in the Fe3+ ion is

5 Correct answer

Answer Details

Read lesson note on Atomic Structure And Bonding (JAMB)

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Question 34 Report

Detergents are better than soaps for washing in hard water because

hard water contains insoluble calcium salts.

they contain bleaching powder.

they contain palmitic acid.

they do not form insoluble calcium and magnesium salts. Correct answer

they are organic compounds.

Answer Details

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

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Question 35 Report

White is NOT a property of metals?

ductile:

malleable

conduct heat and electricity

have many oxidation states Correct answer

high melting points anti boiling points

Answer Details

Read lesson note on Metals And Their Compounds (JAMB)

Read lesson note on Non-metals And Their Compounds (JAMB)

Metals And Their Compounds

Non-metals And Their Compounds

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Question 36 Report

The Kinetic theory can NOT be used to explain

allotropy. Correct answer

Brownian movement.

diffusion.

Tyndal effect.

vaporization.

Answer Details

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

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Question 37 Report

The best way to distinguish between Na₂CO₃and NaHCO₂ is by.

adding an acid.

adding an alkali.

dissolving in water.

exposing to air.

heating. Correct answer

Answer Details

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

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Question 38 Report

The high boiling point of hydrogen fluoride can be explained in terms of

covalent bonds.

dative bonds.

dipole-dipole bonds.

electrovalent (ionic) bonds

hydrogen bonds. Correct answer

Answer Details

Read lesson note on Atomic Structure And Bonding (JAMB)