Post Utme Chemistry Past Questions and Answers

Question 156:

Calculate the minimum volume of the oxygen that is required for complete combustion of a mixture of \(20 \mathrm{~cm}^{3}\) of \(\mathrm{CO}\) and \(10 \mathrm{~cm}^{3}\) of hydrogen.

A. \(5 \mathrm{~cm}^{3}\)
B. \(10 \mathrm{~cm}^{3}\)
C. \(15 \mathrm{~cm}^{3}\)
D. \(20 \mathrm{~cm}^{3}\)

Question 157:

\(\mathrm{HNO}_{3}+\mathrm{H}_{2} \mathrm{O}=\mathrm{H}_{3} \mathrm{O}+\mathrm{NO}_{3}{ }^{-}\)In the reaction above, \(\mathrm{NO}_{3}{ }^{-}\) is the ____________

A. Conjugate acid
B. Acid
C. Conjugate base
D. Base

Question 158:

The pH range of a neutralization product of \(\mathrm{CH}_{3} \mathrm{COOH}\) and \(\mathrm{KOH}\) is ____________

A. \(1-3\)
B. \(7-8\)
C. \(6-7\)
D. \(12-14\)

Question 159:

How much \(\mathrm{NaOH}\) is required to make \(250 \mathrm{~cm}^{3}\) of \(0.1 \mathrm{~mol} / \mathrm{dm}^{3}\) solution?

A. \(10 \mathrm{~g}\)
B. \(1.0 \mathrm{~g}\)
C. \(0.1 \mathrm{~g}\)
D. \(4 \mathrm{~g}\)

Question 160:

\(2 \mathrm{PbO}_{2} \rightarrow 2 \mathrm{PbO}+\mathrm{O}_{2}\)}
In the equation above, the oxidizing agent is ____________

A. \(\mathrm{Pb}^{4+}\)
B. \(\mathrm{Pb}^{2+}\)
C. \(\mathrm{O}^{2-}\)
D. \(\mathrm{O}_{2}\)