Post Utme Chemistry Past Questions and Answers

Question 196:

Ethanol reacts With. aqueous sodium oxoiodate(I) to give a bright yellow solid with a characteristic smell. The product is ____________

A. Trichloramethane
B. Ethanal
C. Iodoethane
D. Triiodomethane

Question 197:

An alkanoic acid has a molar mass of \(102 \mathrm{~g}\). Derive its molecular formula and hence name the acid

A. Propanoic acid
B. Butanoic acid
C. Pentanoic acid
D. Hexanoic acid

Question 198:

Which of the following statements is incorrect?

A. The addition of Water to quicklime is an example of a physical change
B. A chemical change is irreversible and a no substance is formed
C. A physical change can easily be reversed and no new substances are formed
D. Separating a mixture by distillation is an example of physical change

Question 199:

\(20 \mathrm{~g}\) of calcium trioxocarbonate(IV) is heated to a constant mass and \(11.2 \mathrm{~g}\) of calcium oxide is left as residue.
The mass of the gaseous product left is \([C a=40, C 12,0=\) 16J

A. \(11.2 \mathrm{~g}\)
B. \(44 \mathrm{~g}\)
C. \(2.2 \mathrm{~g}\)
D. \(8.8 \mathrm{~g}\)

Question 200:

The vapour pressure of water at \(15^{\circ} \mathrm{C}\) is \(13 \mathrm{mmHg}\). At a barometric pressure of 747 \(\mathrm{mmHg}, 2 \mathrm{dm}^{3}\) of nitrogen gas is collected over water at \(15^{\circ} \mathrm{C}\), the pressure of nitrogen gas is ____________

A. \(760 \mathrm{mmHg}\)
B. \(747 \mathrm{mmHg}\)
C. \(734 \mathrm{mmHg}\)
D. \(114.3 \mathrm{mmHg}\)