Jamb Chemistry 2012 Past Questions and Answers

Question 1:

• JAMB 2012

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

A. Netralization with NaOHfoolowed by filtration
B. Neutralization with NaOH followed by distillation
C. Fractional distillation
D. Filtration followed by distillation

Question 2:

• JAMB 2012

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

A. Netralization with NaOHfoolowed by filtration
B. Neutralization with NaOH followed by distillation
C. Fractional distillation
D. Filtration followed by distillation

Question 3:

• JAMB 2012

How many atoms are present in 6.0g of magnesium?
[Mg = 24, N_A = 6.02 x 10²³ mol^-1]

A. 1.20 x 10²²
B. 2.41 x 10²²
C. 1.51 x 10²³
D. 3.02 x 10²³

Question 4:

• JAMB 2012

50 cm³ of gas was collected over water at 10^oC and 765 mm Hg. Calculate the volume of the gas at s.t.p. if the saturated vapour pressure of water at 10 ^oC is 5mm Hg

A. 49.19 cm ³
B. 48.87 cm ³
C. 48.55 cm ³
D. 48.23 cm ³

Question 5:

• JAMB 2012

An increase in the pressure exerted on gas at a constant temperature results in

A. A decrease in the number of effective collisions
B. A decrease in volume
C. An increase in the average intermolecular distance
D. An increase in volume