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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
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Past Questions

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Question 1 of 20 2,505 total questions
Question 361
jamb 2016
The principle of column chromatography is based on th ability of the constituents to
AReact with the solvent in the column
BReact with each other in the solvent in the column
CDissolve in each other in the column
DMove at different speeds in the column
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Question 362
jamb 2016
The monomer of nylon is
AHydroxybenzene
BHexanedioic acid
CBenzene -1,-4-dicarboxylic acid
DEthane-1,2-diol
View Explanation & Discuss
Question 363
jamb 2016
In the laboratory preparation of chlorine from concentrated hydrochloric acid in the presence of potassuim tetraoxomanganate(VII) the produced is dried by passing it through
AConcentrated tetraoxosulphate (VI) acid
BAnhydrous calcium chloride
CCalcium oxide
DSodium hydroxide
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Question 364
jamb 2016
The enzyme used in the hydrolysis of starch to dextrin and maltose is
AZymase
BSucrase
CAmylase
DLactase
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Question 365
jamb 2016

The condition required for corrosion to take place is the presence of

AOxygen and Carbon (IV) oxide
BWater and Oxygen
CWater and Carbon (IV) oxide and Oxygen
DWater and Carbon (IV) oxide
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Question 366
jamb 2016
In an electrochemical cell, polarization is caused by
AOxygen
BHydrogen
CTetraoxosulphate(IV) acid
DChlorine
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Question 367
jamb 2015

When steam is passed over red hot carbon the substances produced are

Ahydrogen and trioxocarbonate (IV) acid
Bhydrogen, oxygen and carbon (IV) oxide
Chydrogen and carbon (ii) oxide
Dhydrogen and carbon (IV) oxide
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Question 368
jamb 2015
Calculate the relative molecular mass of Limestone CaCO3, (Ca = 40, C =12, O = 16)
A56
B100
C76
D90
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Question 369
jamb 2015
In the electrolysis of brine the anode is
Aplatinum
Bcopper
Czinc
Dcarbon
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Question 370
jamb 2015

The oxidation state of sulphur on H2SO4 acid is

A-4
B+6
C4
D-8
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Question 371
jamb 2015

S block elements of the periodic table one made up of

Agroups 1, 2, 3
Bgroups 1, and 2
Cgroup 3
Dgroup 3 to 7
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Question 372
jamb 2015

In the electrolysis of CuSo4(g) using platinum electrode the reaction at the anode is

A4H+ 4e - 2H2
B4OH= 4e- + 2H2O + O2
C2OH - 2e- = 2OH
D2OH- + 2OH = 2H2O + O2
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Question 373
jamb 2015
The principal constituent of natural gas is
Amethane
Bethane
Cpropane
DButane
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Question 374
jamb 2015
Chlorine consisting of two isotope of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotope of mass number 37
A20
B25
C60
D75
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Question 375
jamb 2015
Chlorine gas turns damp starch-iodide paper
Apink
Bcolourless
Cred
Ddark blue
View Explanation & Discuss
Question 376
jamb 2015
N2O4(g)→ 2NO2(g)

In the endothermic reaction above, more products formed will be favored by
AA constant values
Ban increase in pressure
Ca decrease pressure
Da decrease volume
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Question 377
jamb 2015
what is the pH of 0.00lmoldm3 solution of sodium hydroxide
A14
B13
C12
D11
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Question 378
jamb 2015
Which of the following compounds can be represented by the molecular formula C2 H6O?
Apropanal
Bethanol
Cmethanoic acid
Dglucose
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Question 379
jamb 2015

If glucose is heated with concentrated tetraoxosulphate(vi)acid, it will be dehydrated to?

Acarbon
Bcarbon(iv)oxide
Cethane
Dethanol
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Question 380
jamb 2015
The substance that is used in the steel industry for the removal of carbon. Sulphur and phosphorus impurities from pig iron is
Aoxygen
Bchlorine
Cnitrogen
Dhydrogen
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