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

Question 16:

When ammonium, potassium and Calcium carbonates are each separately heated

A. Non of them will decompose
B. Each of them will decompose to give carbondioxide and the respective oxide
C. Ammonium carbonate and potassium carbonate will not decompose
D. Only ammonium carbonate and calcium carbonate will decompose to carbon dioxide and the respective oxide
E. Ammonium carbonate will decompose to glycocarbon dioxide, water and ammonia

Question 17:

$500c{m}^3$ oxygen was collected over water at ${30}^{\circ }C$ and $752mmHg$ pressure. What is the volume of dry oxygen at STP?
(Vapour pressure of water at ${30}^{\circ }C=32mmHg$ )

A. $475c{m}^3$
B. $415c{m}^3$
C. $586c{m}^3$
D. $500c{m}^3$
E. $427c{m}^3$

Question 18:

Which of the following statements is true?

A. Metals conduct electricity while non-metals do not
B. Metals have high density, non metals have low density
C. Metals form acid oxides, non-metals are below hydrogen
D. Metals Iose electrons while non metals gain electrons during normal reactions

Question 19:

In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?

A. One atom of hydrogen reacts with two atoms of oxygen to give one molecule of water
B. Two atoms of hydrogen react with two atoms of oxygen to give two molecules of water
C. One molecule of oxygen reacts with one molecule of hydrogen to give two molecules of water
D. One molecule of hydrogen reacts with two molecules of oxygen to give three molecules of water
E. One molecule of oxygen reacts with two molecules of oxygen to give two molecules of water

Question 20:

The number of atoms in one mole of a substance is equal to ____________

A. The atomic number
B. The Avogadro number
C. The gas constant
D. The number of neutrons
E. The number of electrons