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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 2017

X(g) + 3Y(g) ---- 2z(g) H = +ve. if the reaction above takes place at room temperature, the G will be

Anegative

Bzero

Cpositive

Dindeterminate

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Question 2

jamb 2017

Ca(OH)2(s) + 2NH4Cl(s) → CaCl2(s) + 2H2O(l) + X. In the reaction above X is

ANO₂

BNH₃

CN₂O

DNO₂

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Question 3

jamb 2017

Water for town supply is chlorinate to make it free from

Abad colour

Bbacteria

Ctemporary hardness

Dpermanent hardness

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Question 4

jamb 2017

The furring of kettles is caused by the presence in water of

Acalcium hydrogentrioxocarbonate (IV)

Bcalcium trioxocarbonate (IV)

Ccalcium tetraoxosulphate (VI)

Dcalcium hydroxide

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Question 5

jamb 2017

Due to the high reactivity of sodium, it is usually stored under

Awater

Bmercury

Cparaffin

Dphenol

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Question 6

jamb 2017

If 100cm³ of oxygen pass through a porous plug is 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is? [O = 16, H = 1]

A10.0s

B12.5s

C17.7s

D32.0s

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Question 7

jamb 2017

Calculate the amount in moles of a gas which occupies 10.5 dm3 at 6 atm and 30oC [R = 0.082 atm dm3 K-1 mol-1]

A2.536

B1.623

C4.736

D0.394

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Question 8

jamb 2017

Ethene is prepared industrially by

AReforming

BPolymerization

CDistillation

DCracking

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Question 9

jamb 2017

A particle that contains 9 protons, 10 neutrons and 10 electrons is

Apositive ion

Bneutral atom of a metal

Cneutral atom of a non-metal

Dnegative ion

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Question 10

jamb 2017

In the laboratory preparation of trioxonitrate (V) acid the nitrogen(iv) oxide formed as a by-product is removed by

Afurther heating

Badding concentrated H₂SO₄

Ccooling the acid solution with cold water

Dbubbling air through the acid solution

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Question 11

jamb 2017

The gas that can be collected by downward displacement of air is

Achlorine

Bsulphur (IV) oxide

Ccarbon (IV) oxide

Dammonia

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Question 12

jamb 2017

An oxide XO₂ has a vapour density of 32. What is the atomic mass of X?

A20

B32

C14

D12

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Question 13

jamb 2017

According to Charle's law, the volume of a gas becomes zero at

A−100°c

B−273°c

C−373°c

D0°c

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Question 14

jamb 2017

The carbon atoms on ethane are

Asp² hybridized

Bsp³ hybridized

Csp⁴ hybridized

Dsp hybridized

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Question 15

jamb 2017

The densities of two gases, X and Y are 0.5gdm^-3 and 2.0gdm^-3 respectively. What is the rate of diffusion of X relative to Y?

A0.1

B0.5

C2.0

D4.0

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Question 16

jamb 2017

The reddish–brown rust on iron roofing sheets consists of

AFe³ + (H₂O)₆

BFeO.H₂O

CFe₂O₃.XH₂O

DFe₃O₄.2H2₂O

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Question 17

jamb 2017

The IUPAC nomenclature of the structure above is

A3-methybut-3-ene

B2-methylbut-1-ene

C2-ethylprop-1-ene

D2-methylbut-2-ene

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Question 18

jamb 2017

Calculate the mass of copper deposited when a current of 0.5 ampere was passed through a solution of copper(II) chloride for 45 minutes in an electrolytic cell. [Cu = 64, F = 96500Cmol^-1]

A0.300g

B0.250g

C0.2242g

D0.448g

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Question 19

jamb 2017

The diagram above. Y is

Afused CaO

BH₂O

CNaOH

DConcentrated H₂SO₄

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Question 20

jamb 2017

In the diagram above. X is

ASO₃

BSO₂

DH₂S

View Explanation & Discuss

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