Post Utme Federal University of Technology, Owerri Chemistry Past Questions and Answers

Question 11:

If concentrated sulphuric acid is added to sugar and warmed gently, the sugar changes from white to brown and "finally to a black mass of carbon. In this reaction, concentrated sulphuric acid is acting as ____________

A. A dying agent
B. An oxidizing agent
C. A dehydrating agent
D. A reducing agent
E. A hydrolyzing agent

Question 12:

When heat is absorbed during a chemical reaction, the reaction is said to be ____________

A. Thermodynamic
B. Exothermic
C. Isothermal
D. Endothermic
E. Thermostatic

Question 13:

The $pH$ of lour solutions $W,X,Y,Z$ are $4,6,8,10$, respectively therefore

A. None of these solutions is acidic
B. The $pH$ of $Y$ is made more acidic by addition of distilled water
C. $Z$ is the most acidic solution
D. $W$ is the most acidic solution
E. $X$ is neutral

Question 14:

Which of the following contains two amphoteric oxides?

A. Sodium oxide, Zinc Oxide, Magnesium oxide
B. Aluminum oxide, calcium oxide, Zinc oxide
C. Potassium oxide, lithium oxide, Carbon dioxide
D. Silver oxide, Lead oxide, Sodium oxide
E. Sulphur dioxide. Aluminum oxide, Carbon monoxide

Question 15:

$50c{m}^3$ of hydrogen are sparked with $20c{m}^3$ of oxygen at ${100}^{\circ }C$ and 1 atmosphere.
The total volume of the residual gases is ____________

A. $50c{m}^3$
B. $10c{m}^3$
C. \(40 cm ^{3}
D. 30 cm ^{3}\)
E. $70c{m}^3$