Post Utme Chemistry Past Questions and Answers

Question 1146:

The decreasing order of the magnitude of energy changes is ____________

A. Phase, chemical, nuclear
B. Chemical, nuclear, phase
C. Nuclear, phase, chemical
D. Nuclear, chemical, phase

Question 1147:

\(0.92 g\) of ethanol raised the temperature of \(100 g\) of water from \(298 K\) to \(312.3 K\) when burned completely. What is the heat of combustion of ethanol?
\([ C =12 ; H =\) \(1 ; O =16\); specific heat capacity of water \(\left.=4.2 Jg ^{-1} K]\)

A. \(+300 kJmol\)
B. \(+3000 kJmol\)
C. \(-300 kJmol\)
D. \(-3000 kJmol\)

Question 1148:

The highest level of molecular disorderliness is found in ____________

A. Ice at \(-10^{\circ} C\)
B. Water at \(100^{\circ} C\)
C. Steam at \(100^{\circ} C\)
D. Ice at \(0^{\circ} C\)

Question 1149:

A reaction is spontaneous at all temperature if ____________

A. \(\Delta G =0\)
B. \(\Delta G >0\)
C. \(\Delta S <0\) and \(\Delta H >0\)
D. \(\Delta S >0\) and \(\Delta H <0\)

Question 1150:

Which of the following reactions of marble with \(100 cm ^{3}\) of \(0.100\) moldm\(^{3}\). HCl is fastest?

A. \(5 g\) of marble lump at \(50^{\circ} C\)
B. \(5 g\) of marble powder at \(50^{\circ} C \quad\)
C. \(5 g\) of marble powder at \(25^{\circ} C\)
D. \(5 g\) of marble lump at \(25^{\circ} C\)