Jamb Chemistry Past Questions and Answers

Question 1451:

• JAMB 2008

Chlorophyll obtained from given leaves of plant can be shown to be composed of more than one coloured component by the technique of

A. Crystallization
B. Hydrolysis
C. Chromatography
D. Sublimation

Question 1452:

• JAMB 2008

In countries where the temperature falls below 273K, salt is always sprinkled on the icy road in order to

A. Lower the melting point of the ice
B. Increase the density of the ice
C. Make the ice impure
D. Raise the melting point of the ice

Question 1453:

• JAMB 2008

2Na_(s) + 2H₂O_(l) → 2NaOH_(aq) + H_2(g)
From the equation above, calculate the mass of sodium hydroxide produced by 2.3g of sodium.
[H = 1, O = 16, Na = 23]

A. 0.40g
B. 0.80g
C. 4.00g
D. 8.00g

Question 1454:

• JAMB 2008

16.8 g of sodium hydrogen trioxocarbonate (IV) is completely decomposed by heat. Calculate the volume of carbon(IV) oxide given off s.t.p
[Na 23, C = 12, O = 16, H = 1, Molar volume of a gas at s.t.p = 22.4 dm³]

A. 22.40 dm³
B. 11.20 dm³
C. 2.24 dm³
D. 1.12 dm³

Question 1455:

• JAMB 2008

300 cm³ of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume

A. 243.75 cm³
B. 369.23 cm³
C. 738.46 cm³
D. 1733.36 cm³