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Chemistry Past Questions

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4,306 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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4,306 questions

Question 1 of 20 4,306 total questions

Question 1141

waec 2005

Which of the following can be used to predict the type of bonding in HCI?

ApH value

BElectronegativity difference

CHeat of neutralization

DHeat of solution

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Question 1142

waec 2005

An element which can exist in two or more forms in the same physical state, exhibits

Aisotopy

Bstructural isomerism

Callotropy

Dvariable valency

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Question 1143

waec 2005

An element X has an atomic number of 16. What is its most likely oxidation state in its binary compounds?

A-3

B-2

C+2

D+4

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Question 1144

waec 2005

Which of the following changes is characteristic of an alpha-particle emission?

Athe nucleus loses two protons and two neutrons

Ba proton combines with an electron giving off heat

Cthe nucleus splits into two equal parts

Dfour neutrons are lost

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Question 1145

waec 2005

Which of the following sets of elements are arranged in order of decreasing atomic size in the Periodic Table?

A₆C, ₄Be, ₇N,₈ O

B₄Be,₆ C,₇ N,₈ O

C₈O, ₇ N, ₆C, ₄Be

D₇N, ₈O, ₆C,₄Be

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Question 1146

waec 2005

What is the mass number of an element having 20 neutrons, 15 protons and 15 electrons?

A15

B30

C35

D50

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Question 1147

waec 2005

The electronic configuration of an element X is 1s²2s ²2s⁶3p ² 3p⁴. It can be deduced that X

ABelongs to group 6 of the Periodic Table

BBelongs to group IV of the Periodic Table

Chas 3 unpaired electrons in its atom

Dhas relative molecular mass of 16

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Question 1148

jamb 2005

The IUPAC nomenclature for the hydrocarbon above is

A1,2 - dimethylprop-2-ene

B1,1- dimethylprop-2-ene

C2-methylbut-3-ene

D3-methylbut-1-ene

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Question 1149

jamb 2005

To obtain pure carbon (II) oxide from its mixture with carbon (IV) oxide, the mixture should be

Apassed over heated copper (II) oxide

Bbubbled through water

Cbubbled through concentrated tetroxosulphate (VI) acid

Dbubbled through sodium hydroxide

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Question 1150

jamb 2005

Which of the following alloys contain iron?

ADuralumin and steel

BBrass and bronze

CSteel and permalloy

DSoft solder and duralumin

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Question 1151

jamb 2005

In a flame test for calcium, the flame appears

Agreen when viewed through a blue glass

Bblue when viewed through a blue glass

Corange -red when viewed through a blue glass

Dbrick-red when viewed through a blue-glass

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Question 1152

jamb 2005

The property used in the industrial preparation of nitrogen and oxygen from air is?

Arate of diffusion

Bdensity

Cboiling point

Dsolubility

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Question 1153

jamb 2005

The ores that can be concentrated by flotation are

Anitride ores

Bsulphide ores

Coxide ores

Dnon-metals

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Question 1154

jamb 2005

Metalloids are also referred to as

Asemi-metals

Bmetals

Ccolloids

Dnon-metals

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Question 1155

jamb 2005

The most abundant element on the earth's crust is

Anitrogen

Bhydrogen

Coxygen

Dfluorine

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Question 1156

jamb 2005

In the diagram above which of the curves illustrates Arrhenius' law?

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Question 1157

jamb 2005

The most suitable metal that can be used as lightning conductor is?

Asilver

Bcopper

Ciron

Daluminium

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Question 1158

jamb 2005

NH\(_4\)Cl(s) ⇌ NH\(_3\)(g) + HCl(g)
The reaction above can only attain equilibrium if

Aa gaseous reactant is added

Bone of the products is removed

Cit is in a closed system

Dit is an open system

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Question 1159

jamb 2005

The gas that can be dried using concentrated tetraoxosulphate (VI) acid is

Ahydrogen bromide

BSulphur (IV) oxide

Chydrogen sulphide

Dammonia

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Question 1160

jamb 2005

N\(_2\)(g) + 3H\(_2\)(g) ↔ 2NH\(_3\)(g) ΔH = - 90 kJ
In the equation above, the yield of ammonia can be decreased by

Aincreasing the pressure

Bremoving the ammonia as it is formed

Cincrease the temperature

Dadding a catalyst

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