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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 311

waec 2021

Consider the structure above

How many carbon atoms does the parent chain contain?

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Question 312

waec 2021

When CuSO\(_{4(aq)}\) is added to Pb(NO\(_{3}\))\(_{2(aq)}\)--------

Athere would be no visible change

Ba blue precipitate would be formed

Cthe resulting solution would become colourless

Da white precipitate would be formed

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Question 313

waec 2021

What would be observed when aqueous ammonia is added in drops and then in excess to a solution of copper(II) ions?

Ablue precipitate is formed which is soluble in excess ammonia

Bbrick red precipitate is produced which is insoluble in excess ammonia

Cwhite precipitate is formed which is excess in ammonia

Dgreen precipitate is formed which is insoluble in excess ammonia

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Question 314

waec 2021

The basic property of salts used as drying agents is by?

Aefforescence

Bhigh melting point

Chygroscopy

Dlow solubility

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Question 315

waec 2021

What number of moles of oxygen would exert a pressure of 10 atm at 320 K in an 8.2 dm\(^{2}\) cylinder?

[R = 0.082 atm dm\(^{3}\) mol\(^{-1}\) K\(^{-1}\)]

A0.32

B1.56

C3.13

D31.25

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Question 316

waec 2021

The most common method of preparing insoluble salts is by

Afiltration

Bdecomposition

Cneutralization

Ddouble decomposition

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Question 317

waec 2021

A molecular of phosphorus is

Adiatomic

Btriatomic

Ctetraatomic

Dmonoatomic

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Question 318

waec 2021

Which of the following gasses is highly soluble in water at room temperature

Aammonia

Bcarbon (IV) oxide

Cchlorine

Dnitrogen

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Question 319

waec 2021

The formation of ethene from dehydration of ethanol can be described as-------

Aan addition reaction

Ban elimination reaction

Can oxidation reaction

Da substitution reaction

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Question 320

waec 2021

Which of the graphs illustrates the variation of the solubility of a salt in water (y-axis), with an increase in temperature (x-axis) if the dissolution process is exothermic?

BII

CIII

DIV

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Question 321

waec 2021

Which of the graphs illustrates the variation of the pH of a given volume of strong acid solution (y-axis) with the volume of strong base titrated against its (x-axis)?

BII

CIII

DIV

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Question 322

waec 2021

Which of the following illustrates the variation of the rate of evolution of gas from a given length of magnesium ribbon (y-axis) with an increase in the concentration of the added (x-axis)?

BII

CIII

DIV

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Question 323

waec 2021

Which of the following pairs of compounds would form a precipitate when their aqueous solutions are mixed?

ANaCl and KNO\(_{3}\)

BKCL and NaNO\(_{3}\)

CK\(_{2}\)SO\(_{4}\) and BaCl\(_{2}\)

DNH\(_{4}\)NO\(_{3}\) and CO\(_{3}\)

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Question 324

waec 2021

The alkanol represented by the structure above is

Aprimary and dihydric

Bsecondary and monohydric

Ctertiary and dihydric

Dsecondary and dihydric

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Question 325

waec 2021

If humid air is polluted by chlorine discharged, the air can be restored by sprinkling

Asolid MnO\(_{2}\)

Bacidified KMnO\(_{4}\)

Cacidified FeSO\(_{4}\)

Dsaturated NaCl(aq)

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Question 326

waec 2021

Cathodic protection of metals is based on

Astandard electrode potential of hydrogen

Bits electrical conductivity

Cnature of oxides formed

Drelative tendencies of oxidation

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Question 327

waec 2021

What is the relative molecular mass of the compound below?

What is the relative molecular mass of the compound below [H = 1.0; C = 12.0; O = 16.0] - SchoolNGR

[H = 1.0; C = 12.0; O = 16.0]

A137

B136

C64

D59

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Question 328

waec 2021

The ratio of carbon atoms of hydrogen atoms in a hydrocarbon is 1:2. If its molecular mass is 56, what is its molecular formula?

AC\(_{3}\)H\(_{6}\)

BC\(_{4}\)H\(_{8}\)

CC\(_{2}\)H\(_{4}\)

DCH\(_{2}\)

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Question 329

waec 2021

Which of the following oxide causes acid rain?

ACO

BNO

CH\(_{2}\)O\(_{2}\)

DNO\(_{2}\)

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Question 330

waec 2021

The hydrolysis of proteins by diluting mineral acids produces

Asucrose

Bglucose

Camino acids

Dfatty acids

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