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Chemistry Past Questions

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1,623 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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1,623 questions

Question 1 of 20 1,623 total questions

Question 201

waec 2017

A primary alkanol has a molecular mass of 60. What is the structural formula of the compound? [C= 12.0, H= 1.0, O= 16.0)

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Question 202

waec 2017

The real harmful effect of the release of chlorofluorocarbons into the atmosphere is that it eventually causes

Aexcessive ultraviolet light from the sun to reach the earth surface

Bexcessive release of infrared light from the sun to the earth surface

Ccorrosive effect of the chemicals on humans and animals

Dacidic effect of chemicals on humans

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Question 203

waec 2017

The IUPAC name for the compound \(ClCH_{2}CH_{2}OH\) is

A1- chloropropanol

B2-chloropropanol

C1-chloroethanol

D2-chloroethanol

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Question 204

waec 2017

The condensation of two units of glucose will produce a dissacharide with the formula \(C_{12}H_{22}O_{11}\) which is

Asucrose

Bmaltose

Cgalactose

Dmannose

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Question 205

waec 2017

Fats and oils can be obtained from any of the following sources except

Aparaffin oil

Banimals

Cgroundnuts

Dpalm kernel

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Question 206

waec 2017

Which of the following pairs of gases are pollutants from car exhaust?

ANitrogen(II) oxide and Carbon(IV) oxide

BCarbon(IV) oxide and Nitrogen

CCarbon(II) oxide and Sulphur(IV) oxide

DCarbon(II) oxide and oxygen

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Question 207

waec 2017

The name of the compound \(C_{4}H_{9}COOC_{3}H_{7}\) is

Apropyl pentanoate

Bpentyl propanoate

Cbutyl propanoate

Dpropyl butanoate

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Question 208

waec 2017

Classification of alkanols is based on the

Anumber of carbon atoms present in the compound

Bmolecular mass of the compound

Cmolecular formula of the compound

Dnumber of alkyl groups bonded to the carbon having the hydroxyl group

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Question 209

waec 2017

Calculate the mass of copper deposited if a current of 0.45A flows through \(CuSO_{4}\) solution for 1hour 15mins. [Cu=64.0, S= 32.0, O =16.0, 1F= 96500C]

A6.40g

B0.67g

C0.64g

D0.45g

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Question 210

waec 2017

Which of the following factors characterize members of the same homologous series?

AThe chemical property change gradually throughout the series

Bphysical properties of members are similar

CThey have the same molecular formular

DSuccessive members undergo changes in molecular formula by \(CH_{2}\)

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Question 211

waec 2017

Consider the following reaction equation: \(2NO_{(g)} + O_{{2}{(g)}} \to 2NO_{{2}{(g)}}\). What is the change in the oxidation number of nitrogen?

A+2 to 0

B+2 to -2

C+2 to +4

D+4 to +2

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Question 212

waec 2017

The common feature of reactions at the anode is that

Aelectrons are consumed

Bions are reduced

Coxidation is involved

Dthe electrode dissolves

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Question 213

waec 2017

Chemical reactions occurs when the colliding reactants have energy that is

Aless than the activation energy

Bgreater than the activation energy

Cgreater than the energy of the product

Dless than the energy of effective collision

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Question 214

waec 2017

Soluble salts can be prepared by the following methods except

Aneutralization

Breaction of an acid with trioxocarbonate(IV) salt

Cdouble decomposition

Dreaction of an acid with electropositive metals

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Question 215

waec 2017

The property of a chemical reaction that is affected by the presence of a catalyst is

Aactivation energy

Bfree energy

Cequilibrium position

Denthalpy change

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Question 216

waec 2017

If 0.2g of a salt is required to saturate 200\(cm^{3}\) of water at room temperature, what is the solubility of the salt?

A0.2\(gdm^{-3}\)

B1.0\(gdm^{-3}\)

C2.0\(gdm^{-3}\)

D5.0\(gdm^{-3}\)

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Question 217

waec 2017

Solubility curve can be used in the determination of the

Aamount of crystals formed

Bamount of solvent that can be recovered

Camount of solid drugs in a given solution

Dtemperature of the solution

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Question 218

waec 2017

When water was added to a white anhydrous substance X, the colour changed to blue. X is

A\(CuSO_{4}\)

B\(FeSO_{4}\)

C\(Na_{2}SO_{4}\)

D\(PbSO_{4}\)

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Question 219

waec 2017

Potassium Chloride solid does not conduct electricity because

Ait is a covalent compound

Bstrong cohesive forces make its ions immobile

Cstrong cohesive force makes its molecule immobile

Deach of potassium and chlorine structures contain noble gas structure

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Question 220

waec 2017

Halogens generally react with metals to form

Aalkalis

Bacids

Cbases

Dsalts

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