Post Utme Chemistry Past Questions and Answers

Question 161:

A current of \(0.5\) A flows for 1930 seconds and deposits \(0.325\) \(\mathrm{g}\) of metal \(M\). If the charge is \(+2\), the relative molecular mass is ____________

A. \(65 \mathrm{~g}\)
B. \(32 \mathrm{~g}\)
C. \(24 \mathrm{~g}\)
D. \(40 \mathrm{~g}\)

Question 162:

Emission of chlorofluorocarbon (CFC) into the atmosphere causes ____________

A. Global warming
B. Acid rain
C. Depletion of ozone layer
D. Greenhouse effect

Question 163:

The diagram above shows the reaction path of an exothermic reaction.
The heat of reaction is represented by

A. I
B. II
C. III
D. IV

Question 164:

Which of the following samples will react fastest with dilute HCL?

A. \(10 \mathrm{~g}\) of lumps of \(\mathrm{CaCO}_{3}\) at \(25^{\circ} \mathrm{C}\)
B. \(10 \mathrm{~g}\) of powdered \(\mathrm{CaCO}_{3}\) at \(25^{\circ} \mathrm{C}\)
C. \(10 \mathrm{~g}\) of lumps of \(\mathrm{CaCO}_{3}\) at 50 \({ }^{\circ} \mathrm{C}\)
D. \(10 \mathrm{~g}\) of powdered \(\mathrm{CaCO}_{3}\) at \(50^{\circ} \mathrm{C}\)

Question 165:

The colour exhibited by copper in a flame test is ____________

A. Green
B. Lilac
C. Blue-green
D. Crimson