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Chemistry Past Questions

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49 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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Past Questions

49 questions

Question 1 of 20 49 total questions

Question 1

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 2

jamb 1990

Select the right answer from the structure above.Which of the following compounds represents the polymerization product of ethyne?

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Question 3

jamb 1990

The above reaction is an example of

Aa displacement reaction

Ba neutralization reaction

Can elimination reaction

Dsaponification

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Question 4

jamb 1990

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

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Question 5

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

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Question 6

jamb 1990

Use the graph above to answer this question. The structure of cis-2-butene is

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Question 7

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

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Question 8

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

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Question 9

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 10

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 11

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 12

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 13

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

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Question 14

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

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Question 15

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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Question 16

jamb 1990

A blue solid, T, which weighed 5.0g was placed on a table. After 8 hours, the resulting pink solid was found to weigh 5.5g. It can be inferred that substance T?

Ais deliquescent

Bis hygroscopic

Chas some molecules of water of crystallization

Dis efflorescent

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Question 17

jamb 1990

10.0 dm³ of air containing H₂S as an impurity was passed through a solution of Pb(NO₃)₂ until all the H₂S had reacted. The precipitate of PbS was found to weigh 5.02 g. According to the equation:

Pb(NO₃)₂ + H₂S → PbS + 2HNO₃ the percentage by volume of hydrogen sulphide in the air is?

(Pb = 207, S = 32, GMV at s.t.p = 22.4dm³)

A50.2

B47.0

C4.70

D0.47

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Question 18

jamb 1990

Chlorine, consisting of two isotopes of mass numbers 35 and 37, has an atomic mass of 35.5.
The relative abundance of the isotope of mass number 37 is?

A20

B25

C50

D75

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Question 19

jamb 1990

X(g) → X\(^-\)(g). The type of energy involved in the above transformation is?

Aionization energy

Bsublimation energy

Clattice energy

Delectron affinity

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Question 20

jamb 1990

Which of the following terms indicates the number of bonds that can be formed by an atom?

AOxidation number

BValence

CAtomic number

DElectronegativity

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