Chemistry Past Questions

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Past Questions

2,505 questions
Question 1 of 20 2,505 total questions
Question 521
jamb 2009

The oxidation of ammonia in excess air produces?

ANO
BN2O
CNO2
DN2O4
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Question 522
jamb 2009
The equilibrium of an endothermic reaction which proceeds with an increase in volume can be shifted in the reverse direction by
Aincreasing the temperature and decreasing the pressure
Bincreasing the pressure and increasing the temperature
Cdecreasing the temperature and increasing the pressure
Ddecreasing the pressure and decreasing the temperature
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Question 523
jamb 2009

CuO(s) + H\(_2\)(g) ↔ Cu(s) + H\(_2\)O(g)
What is the effect of increasing the pressure on the equilibrium reaction above?

AThe equilibrium is shifted to the left
BThe equilibrium is shifted to the right
CThere is no effect
DMore H2(g) is produced
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Question 524
jamb 2009

A catalyst increase the rate of a chemical reaction by providing a path that?

Araise the activiation energy
Bincrease the temperature
Clowers the activation energy
Dincrease the concentration
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Question 525
jamb 2009

In the diagram above, which of the curves represents the evolution of oxygen with time in the equation 2KClO3(s) → 2KCl(s) + 3O2(g)?

AX
BY
CZ
DR
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Question 526
jamb 2009

Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth - to - mouth to each other at room temperature. The entropy in the mixture of gases is likely to?

Aremain unchange
Bincrease
Cdecrease
Dchange
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Question 527
jamb 2009

C(s) + H2O(g) → H2(g) + CO2(g)
ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is?

Anot feasible
Bat equilibrium
Cfeasible
Dexothermic
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Question 528
jamb 2009
What current will deposit 3.25g of zinc in 2hrs?
[Zn = 65, F = 96500 mol-]
A3.25A
B2.00A
C1.34A
D0.67A
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Question 529
jamb 2009

Which of the following metals is purified commercially by electrolysis?

AZn
BFe
CSn
DCu
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Question 530
jamb 2009

The oxidation state of Cr in K\(_2\)Cr\(_2\)O\(_7\) is?

A+7
B+6
C+5
D4
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Question 531
jamb 2009

The colour changes observed when testing for reducing agents using acidified potassium heptaoxodichromate (VI) solution is?

Ayellow to purple
Borange to green
Cgreen to orange
Dpurple to yellow
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Question 532
jamb 2009

The salt formed from a reaction between citric acid and sodium hydroxide in solution will be?

Aacidic
Bbasic
Ccomplex
Dneutral
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Question 533
jamb 2009
What volume of 1.5M solution of KOH would contain 0.045 moles
A67.50 cm3
B30.00 cm3
C6.75 cm3
D3.00 cm3
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Question 534
jamb 2009

The acid used in electrolysis of water is dilute?

AHNO3
BCH3COOH
CH2SO4
DHCl
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Question 535
jamb 2009
The major source of oxides of nitrogen is from the burning of
Acoal
Bwood
Cfuel
Dchlrofluorocarbons
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Question 536
jamb 2009
For a given solute, the concentration of its saturated solution in different solvents are
Athe same at the same temperature
Bdifferent at the same temperature
Cthe same at different temperature
Dconstant
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Question 537
jamb 2009
If 10.5g of lead (II) trioxonitrate (V) is dissolved in 20cm3 of distilled water at 18oC, the solubility of the solute in mol dm-3 is
[Pb = 207, N = 14, O = 16]
A1.60
B5.25
C16.00
D525.00
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Question 538
jamb 2009

Water can be obtained as the only product during the?

Acombustion of hydrocarbons
Bneutraliization of an acid by base
Ccombustion of hydrogen
Delectrolysis of brine
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Question 539
jamb 2009

When sodium trioxocarbonate (IV) decahydrate loses its water of crystallization to the atmosphere, the process is?

Adeliquescence
Befflorescence
Chygroscopic
Deffervesecence
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Question 540
jamb 2009

The mixture of gases used in a photographer's flash tube is?

Aargon and krypton
Bkrypton and xenon
Chelium and argon
Dargon and xenon
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