Post Utme Chemistry Past Questions and Answers

Question 216:

Haze is an example of ____________

A. Colloid
B. Suspension
C. Emulsion
D. Aerosol

Question 217:

The volume of \(0.20 \mathrm{~mol} \mathrm{} \mathrm{dm}^{-3}\) \(\mathrm{H}_{2} \mathrm{SO}_{4}\) that will exactly neutralize \(25 \mathrm{~cm}^{3}\) of \(0.05 \mathrm{~mol} \mathrm{} \mathrm{dm}^{-3} \mathrm{KOH}\) solution is ____________

A. \(3.1 \mathrm{~cm}^{3}\)
B. \(10.4 \mathrm{~cm}^{3}\)
C. \(15.6 \mathrm{~cm}^{3}\)
D. \(26.2 \mathrm{~cm}^{3}\)

Question 218:

If the relative rate of diffusion of a gas is \(0.25\) and that of \(\mathrm{Cl}_{2}\) under the same condition is \(0.20\); calculate the relative molecular mass of the gas. 3. A solution of calcium bromide contains \(20 \mathrm{~g} / \mathrm{dm} 3\). What is the molar concentration of calcium bromide relative to bromide ions? \([\mathrm{Ca}=40, \mathrm{Br}=80]\)

A. \(22.7\)
B. \(45.4\)
C. \(68.1\)
D. \(90.8\)

Question 219:

The oxidation states of Chlorine in. \(\mathrm{HOCl}_{3}, \mathrm{HClO}_{3}, \mathrm{HClO}_{4}\) respectively are ____________

A. \(-1,+5\) and \(+7\)
B. \(-1,-5\) and \(+7\)
C. \(+1,+3\) and \(+4\)
D. \(+1,+5\) and \(+7\)

Question 220:

What is the sign of \(\Delta H\) and \(\Delta S\) in the following reaction? \(\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})}
ightarrow \mathrm{CO}_{2(\mathrm{~g})} \Delta \mathrm{H} \Delta \mathrm{S}\)

A. \(+0\)
B. \(-+\)
C. \(+-\)
D. \(-0\)