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Chemistry Past Questions

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

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Past Questions

4,306 questions

Question 1 of 20 4,306 total questions

Question 1101

jamb 2006

In the diagram above, the respective activation energies for the catalyzed and uncatalyzed reactions in kJ are

A45 and 50

B50 and 45

C30 and 35

D40 and 45

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Question 1102

jamb 2006

Which of the following functional groups will give gas bubbles when treated with a saturated solution of sodium hydrogen trioxocarbonate (IV)?

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Question 1103

jamb 2006

2-methylbut-2-ene has the structure

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Question 1104

jamb 2006

The oxidation of the compound above produces

A2-butanone

B2-butanal

C3-butanal

D3-butanone

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Question 1105

jamb 2006

In the diagram above, mixture Y is

ANH₄NO_3(s) + CaSO_4(s),/sub>

BNH₄Cl_(s) + NaNO_2(s)

CNH₄NO_2(s) + Na₂SO_4(s)

DNH₄Cl_(s) + Ca(OH)_2(s)

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Question 1106

jamb 2006

In the diagram above, gas X is

Ahydrogen

Bchlorine

Coxygen

Dhydrogen chloride

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Question 1107

jamb 2006

5SO\(_2\)(g) + 2KMnO\(_4\)(aq) + 2H\(_2\)O(l) → K\(_2\)SO\(_4\) + 2MnSO\(_4\)(aq) + 2H\(_2\)SO\(_4\)(aq)
In the reaction above, the products give a

Apurple solution

Bpurple precipitate

Ccolourless precipitate

Dcolourless solution

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Question 1108

jamb 2006

If the heat of combustion of hydrogen is -285.8kJ,
What is the heat of formation of water?

A+571.6 kJ

B-571.6 kJ

C-285.8 kJ

D+285.8 kJ

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Question 1109

jamb 2006

Na\(_2\)CO\(_3\)(g) + 2HCl(aq) → 2NaCl(aq) + H\(_2\)O(l) + CO\(_2\)(g)
How many moles of sodium trioxocarbonate (IV) are there in a 25 cm\(^3\) solution which required 10cm\(^3\) of 0.05 mol dm\(^3\) hydrochloric acid solution to neutralize it?

A1.000 mole

B0.100 mole

C0.010 mole`

D0.111 mole

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Question 1110

jamb 2006

In the electrolysis of CuSO\(_4\)(g) using platinum electrodes, 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 1111

jamb 2006

In which of the following is the oxidation number of sulphur equal to - 2?

ASO₃

BS₈

CH₂S

DSO₂

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Question 1112

jamb 2006

The solution that will conduct the highest amount of electricity is?

A0.5 mol dm^-3 of hydrochloric acid

B2.0 mol dm^-3 of hydrochloric acid

C0.5 mol dm^-3 ethanoic acid

D2.0 mol dm^-3 ethanoic acid

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Question 1113

jamb 2006

Zinc and carbon rods are used as anode and cathode respectively in a

ALeclanche cell

Blead accumulator

CDaniel cell

Dvoltaic cell

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Question 1114

jamb 2006

H\(_2\)(g) + Br\(_2\)(g) → 2HBr(g)
The above reaction is carried out at 25\(^0\)C. ΔH is -72 kJ mol-1 and ΔS is - 106 J mol-1K-1, the reaction will?

Anot proceed spontaneously at the given

Bproceed spontaneously at the given temperature

Cproceed in the reverse direction at the given temperature

Dproceed spontenously at lower temperature

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Question 1115

jamb 2006

The ion that can be used as an oxidizing agent is

AAu³⁺

BFe³⁺

CClO^-

DCa²⁺

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Question 1116

jamb 2006

2C\(_2\)H\(_2\)(g) + 5O\(_2\)(g) → 4CO\(_2\)(g) + 2H\(_2\)O(g)
In the reaction above, the mass of carbon(IV)oxide produced on burning 78 g of ethyne is
[C =12, O = 16, H = 1]

A264 g

B39 g

C352 g

D156 g

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Question 1117

jamb 2006

If 30cm\(^3\) of gas at 50\(^0\)C is warmed to 80\(^0\)C at a fixed pressure, the fractional increase in volume is

A0.009

B0.093

C0.910

D1.090

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Question 1118

jamb 2006

The idea of planetary electron was that of

ARutherford

BThompson

CBohr

DDalton

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Question 1119

jamb 2006

The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is

Adissolution → dryness → filtration → evaporation

Bfiltration → sublimation → evaporation → dryness

Csublimation → dissolution → filtration → evaporation

Ddissolution → filtration → sublimation → evaporation

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Question 1120

jamb 2006

A decrease in atomic size and an increase in nuclear charge across a period lead to

Aan increase in the tendency to lose electron

Ban increase in chemical reactivity

Ca decrease in electropositivity

Da decrease in covalency in bond formation

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