Classroom

Chemistry Past Questions

Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.

2,505 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

Select subject

Download PHP app Ask a Question Check Syllabus Past Question Videos Topic Video Lessons

Take a test

Custom CBT

Create and set up a CBT environment with your preferred subjects.

JAMB CBT Simulator

Practice JAMB CBT with real UTME past questions in CBT format.

WAEC CBT Practice 2026 Simulator

CB-WASSCE styled past question practice.

NECO CBT Practice 2026 Simulator

SSCE & GCE styled past question practice.

Past Questions

2,505 questions

Question 1 of 20 2,505 total questions

Question 1061

jamb 1985

Copper sulphate solution is electolysed using platinum electrodes A. current of 0.193 amperes is passed for 2hrs. How many grams of copper are deposited? (cu = 63.5, F = 96500 coulombs)

A0.457g

B0.500g

C0.882g

D0.914g

E1.00g

View Explanation & Discuss

Question 1062

jamb 1985

In what respect will two dry samples of nitrogen gas differ from each other if sample 1 is prepared by completely removing CO₂ and O₂ from air, and sample 2 is prepared by passing purified nitrogen(i)oxide over heated copper? sample 1 is

Apurer than sample 2

Bslightly denser than sample 2

Cin all respects the same as sample 2

Dcolourless but sample 2 has a light brown colour

Eslightly less reactive than sample 2

View Explanation & Discuss

Question 1063

jamb 1985

The boiling point of water, ethanol, toluene and butan-2-ol are 373.0k, 351.3k, 383.6k and 372.5k respectively. Which liquid has the highest vapour pressure at 323.0k?

Awater

Btoluene

Cethanol

Dbutan-2-ol

Enone

View Explanation & Discuss

Question 1064

jamb 1985

Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because

Azinx is not rendered passive by acid

Bhydrogen produced is oxidized to water

Coxides of nitrogen are produced

Dall nitrates are soluble in water

Etrioxonitrate(v)acid is a strong acid

View Explanation & Discuss

Question 1065

jamb 1985

A certain volume of gas at 298k is heated such that its volume and pressure are now four times the original values. What is the new temperature?

A18.6k

B100.0k

C298.0k

D1192.0k

E4768.0k

View Explanation & Discuss

Question 1066

jamb 1985

Some properties of chemical substances are mentioned below... i. sour taste ii. slippery touch iii. yields alkaline gas with ammonium salt iv. has pH less than 7 v. turns phenolphthalein pink.

Which of the above are NOT typical properties of alkalis?

Ai, iv and v

Biv and v

Ci and iv

Dii and v

Eii, iii and iv

View Explanation & Discuss

Question 1067

jamb 1985

3.0g of a mixture of potassium carbonate and potassium chloride were dissolved were dissolved in a 250cm\(^3\) standard flask. 25cm\(^3\) of this solution required 40.00cm\(^3\) of 0.1M HCl for neutralization. What is the percentage by weight of K\(_2\)CO\(_3\) in the mixture ? (K = 39, O = 16, C = 12)

A60

B72

C82

D89

E92

View Explanation & Discuss

Question 1068

jamb 1985

Given that the molecular mass of iron is 56 and that of oxygen is 16, how many moles of iron(iii)oxide will be contained in 1kg of the compound?

A25.0 moles

B12.5 moless

C6.25 moles

D3.125 moles

E0.625 moles

View Explanation & Discuss

Question 1069

jamb 1985

Hydrogen diffuses through a porous plug

Aat the same rate as oxygen

Bat a slower rate than oxygen

Ctwice as fast as oxygen

Dthree times as fast as oxygen

Efour times as fast as oxygen

View Explanation & Discuss

Question 1070

jamb 1985

In the experiment, which of the following observations would suggest that a solid sample is a mixture? The

Asolid can be ground to a fine powder

Bdensity of the solid is 2.25gdm^-3

Csolid begins to melt at 573k but is not completely melted until 648k

Dsolid absorbs moisture from the atmosphere and turns into liquid

Esolid melts at 300k

View Explanation & Discuss

Question 1071

jamb 1985

0.499g 0f CuSO₄.xH₂O when heated to constant weight gave a residue of 0.346g. the value of x is? (Cu = 63.5, S = 32.0, O = 16, H = 1)

A0.5

B2.0

C3.0

D4.0

E5.0

View Explanation & Discuss

Question 1072

jamb 1985

An organic compound contains 72% carbon, 12% hydrogen and 16% oxygen by mass. The empirical formula of the compound is

AC₈H₂₂O₃

BC₆H₁₀O₃

CC₁₂H₁₂O

DC₆H₁₂O

EC₃H₆O

View Explanation & Discuss

Question 1073

jamb 1985

Which of the following conduct electricity?

Asulfur

Bgraphite

Cdiamond

Dred phosphorus

Eyellow phosphorus

View Explanation & Discuss

Question 1074

jamb 1985

Use the following option above to answer this question. Which of the following is the functional group of carboxylic acids?

View Explanation & Discuss

Question 1075

jamb 1985

The I.U.P.A.C name for the compound

A2-methyl-3-pentene

B4-methyl-2-pentane

C2-methyl-2-pentene

D4-methylpent-2-ene

E2-methyl-3-pentane

View Explanation & Discuss

Question 1076

jamb 1985

The oxidation of

A2-butanone

B2-butanal

Cbutane

Dbutanoic acid

E3-butanal

View Explanation & Discuss

Question 1077

jamb 1985

Use the above options to the question. The products formed on hydrolysis of

View Explanation & Discuss

Question 1078

jamb 1985

The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. If the molar mass of X is 36 g, the number of moles of X dissolved at 343 K is

A0.2 moles

B0.7 moles

C1.5 moles

D2.0 moles

E3.0 moles

View Explanation & Discuss

Question 1079

jamb 1985

The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. If 80 g each of X and Y are taken up in 100 g of water at 353 K we shall have

Aonly 10g of X undissolved

Bonly 16 g of Y undissolved

C10 g of X and 16 g of Y undissolved

Dall X and Y dissolved

Eall X and Y undissolved

View Explanation & Discuss

Question 1080

jamb 1985

The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. At room temperature (300 K)

AY is twice as soluble as X

BX is twice as soluble as Y

CX and Y are soluble to the same extent

DX is three times as soluble as Y

EY is three times as soluble as X

View Explanation & Discuss

Question Navigator

Current

Chemistry Past Questions

Take a test

Custom CBT

JAMB CBT Simulator

WAEC CBT Practice 2026 Simulator

NECO CBT Practice 2026 Simulator

Past Questions

Question Navigator

MathsFaculty