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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.

45 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

45 questions
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Question 1 of 5 45 total questions
Question 21
jamb 2012
2H2(g) + O2(g) → 2H2 O(g)
In the reaction above, what volume of hydrogen would be left over when 300 cm3 of oxygen and 1000 cm3 of hydrogen are exploded in a sealed tube?
A200 cm3
B400 cm3
C600 cm3
D700 cm3
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Question 22
jamb 2012
An increase in the pressure exerted on gas at a constant temperature results in
Aa decrease in the number of effective collisions
Ba decrease in volume
Can increase in the average intermolecular distance
Dan increase in volume
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Question 23
jamb 2012

50 cm\(_3\) of gas was collected over water at 10ºC and 765 mm Hg. Calculate the volume of the gas at s.t.p. if the saturated vapour pressure of water at 10ºC is 5mm Hg

A49.19 cm 3
B48.87 cm 3
C48.55 cm 3
D48.23 cm 3
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Question 24
jamb 2012
How many atoms are present in 6.0g of magnesium?
[Mg = 24, NA = 6.02 x 1023 mol-1]
A1.20 x 1022
B2.41 x 1022
C1.51 x 1023
D3.02 x 1023
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Question 25
jamb 2012

Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid?

Anetralization with NaOHfoolowed by filtration
Bneutralization with NaOH followed by distillation
Cfractional distillation
Dfiltration followed by distillation
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