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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.

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

4,306 questions
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Question 1 of 20 4,306 total questions
Question 1811
waec 1990
The heat accompanying the reaction represented by the equation H2O (l) → H 2O(g) is described as the heat of
Asolution
Bneutralization
Cvaporization
Dsublimation
Eactivation
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Question 1812
waec 1990
The electronic configuration 1s2 22s 22p 63s23p 6 is that of a
Anoble gas
BGroup ll element
CGroup lll element
DGroup V element
EGroup VI element
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Question 1813
waec 1990
A sample of orange juice is suspected to have been contaminated with a yellow dye. Which of the following methods can be used to detect the dye?
ADecantation
BChromatography
CDistillation
DFiltration
EEvaporation
View Explanation & Discuss
Question 1814
waec 1990

Which of the following reaction will not take place under normal conditions?

AZn(s) + 2HCl → ZnCI2(aq) + H 2(g)
BFe (s) + H 2SO4(aq) → FeSO4(aq) + H2(g)
CCu (s) + 2HCI (aq) → CuCI 2(aq) + H2(g)
DCa(s) + 2H 2O (1) → Ca(OH)2(g) + H2(g)
E2Na(s) + 2H 2O (1) → 2NaOH(aq) + H2(g)
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Question 1815
waec 1990
Catalytic hydrogenation of oils results in the production of
Asoaps
Bdetergents
Calkanes
Dbutter
Emargarine
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Question 1816
jamb 1990
The Avogadro number of 24g of magnesium is the same as that of
A1g of hydrogen molecules
B16g of oxygen molecules
C32g of oxygen molecules
D35.5g of chlorine molecules
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Question 1817
jamb 1990
Select the right answer from the structure above.Which of the following compounds represents the polymerization product of ethyne?
AA
BB
CC
DD
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Question 1818
jamb 1990
The above reaction is an example of
Aa displacement reaction
Ba neutralization reaction
Can elimination reaction
Dsaponification
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Question 1819
jamb 1990

CH3-C = CH \(\frac{Na}{liq NH_3}\)> P, Compound P, in the above reaction, is

AA
BB
CC
DD
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Question 1820
jamb 1990

What is the IUPAC name for the hydrocarbon?

A2-ethyl-4-methylpent-2-ene
B3,5-dimethylhex-3-ene
C2,4-dimethylhex 3-ene
D2-methyl-4-ethylpent-3-ene
View Explanation & Discuss
Question 1821
jamb 1990
Use the graph above to answer this question. The structure of cis-2-butene is
AA
BB
CC
DD
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Question 1822
jamb 1990
Changes in the physical in the scheme above.The letter X,Y and Z respectively represent
Asublimation, condensation and freezing
Bsublimation, vapourization and solidification
Cfreezing, condensation and sublimation
Devaporation, liquefaction and solidification
View Explanation & Discuss
Question 1823
jamb 1990
0.1 faraday of electricity deposited 2.95 g of nickel during electrolysis of an aqueous solution.
Calculate the number of moles of nickel that will be deposited by 0.4 faraday?

(Ni = 58.7)
A0.20
B0.30
C0.04
D5.87
View Explanation & Discuss
Question 1824
jamb 1990
If 10.8 g of silver is deposited in a silver coulometer volume of oxygen liberated is?
A0.56 dm3
B5.60 dm3
C11.20 dm3
D22.40 dm3
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Question 1825
jamb 1990

What volume of 11.0 M hydrochloric acid must be dilute to obtain 1 dm3 of 0.05 M acid?

A0.05 dm3
B0.10 dm3
C0.55 dm3
D11.0 dm3
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Question 1826
jamb 1990
What is the concentration of H+ ions in moles per dm3 of a sodium of pH 4.398?
A4.0 χ 10-5
B0.4 χ 10-5
C4.0 χ 10-3
D0.4 χ 10-3
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Question 1827
jamb 1990
2.0g of a monobasic acid was made up to 250 cm3 with distilled water. 25.00 cm3 of this solution required 20.00cm3 of 0.1 M NaOH solution for complete neutralization. The molar mass of the acid is?
A200 g
B160 g
C100 g
D50 g
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Question 1828
jamb 1990

Na2C2O4 + CaCl2 → CaC2O4 + 2NaCl. Given a solution of 1.9g of sodium oxalate in 50g of water at room temperature, calculate the minimum volume of 0.1 M calcium oxalate using the above equation?

A1.40 χ 102 dm3
B14.0 χ 102 cm3
C1.40 χ 10-2 dm-2
D14.0 χ 10-2 cm3
View Explanation & Discuss
Question 1829
jamb 1990
Smoke consist of?
Asolid particles dispersed in liquid
Bsolid or liquid particles dispersed in gas
Cgas or liquid particles dispersed inliquid
Dliquid particles dispersed inliquid
View Explanation & Discuss
Question 1830
jamb 1990
The solubility in moles per dm3 of 20g of CuSO4 dissolve in 100 of water at 180°C is?

(Cu = 63.5, S = 32, O = 16)
A0.13
B0.25
C1.25
D2.00
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