POST UTME CALEB UNIVERSITY 2017 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
The s\tandard enthalpy of formation of H2O(l) is -285.8 kJ/mol. Calculate the s\tandard enthalpy of combustion of hydrogen.
A. -286.0 kJ/mol
B. -286.1 kJ/mol
C. -286.2 kJ/mol
D. -286.3 kJ/mol
Question 2
A 1.00 L sample of a gas at 25°C and 1.00 atm is collected over water at 25°C. If the vapor pressure of water at 25°C is 23.8 mmHg, what is the partial pressure of the gas?
A. 0.977 atm
B. 0.983 atm
C. 0.989 atm
D. 0.995 atm
Question 3
A 0.5 M solution of NaOH is prepared by dissolving 25 g of NaOH in water to make 1 L of solution. Calculate the molarity of the solution.
A. 0.25 M
B. 0.5 M
C. 0.75 M
D. 1.0 M
Question 4
A solution containing 0.500 M NaCl is prepared by dissolving 25.0 g of NaCl in 1.00 L of water. What is the concentration of Cl^- ions in the solution?
A. 0.250 M
B. 0.500 M
C. 0.750 M
D. 1.00 M
Question 5
The s\tandard enthalpy of combustion of methane is -890.3 kJ/mol. Calculate the s\tandard enthalpy of formation of methane.
A. -74.8 kJ/mol
B. -75.0 kJ/mol
C. -75.2 kJ/mol
D. -75.4 kJ/mol
Question 6
The atomic radius of an element is 100 pm. If the element has an electron configuration of [Ar] 4s^2 3d^5, what is the expected oxidation state of the element in its compounds?
A. +2
B. +3
C. +4
D. +5
Question 7
Determine the s\tandard enthalpy of formation of CaCO3(s) from the following data: ΔHf(CaO(s)) = -635.09 kJ/mol, ΔHf(CO2(g)) = -393.51 kJ/mol, ΔHf(C(s)) = 0 kJ/mol.
A. -1206.60 kJ/mol
B. -1206.10 kJ/mol
C. -1207.10 kJ/mol
D. -1207.60 kJ/mol
Question 8
A 0.5 M solution of NaOH is prepared by dissolving 25 g of NaOH in water to make 1 L of solution. Calculate the molarity of the solution.
A. 0.25 M
B. 0.5 M
C. 0.75 M
D. 1.0 M
Question 9
The half-reaction for the reduction of MnO4- is: MnO4- + 8H+ + 5e- → Mn2+ + 4H2O. What is the s\tandard reduction potential of MnO4-?
A. +1.51 V
B. +1.51 V
C. +1.51 V
D. +1.51 V
Question 10
A 1 M solution of HCl is prepared by dissolving 36.5 g of HCl in water to make 1 L of solution. Calculate the molarity of the solution.
A. 1.0 M
B. 1.1 M
C. 1.2 M
D. 1.3 M
Question 11
A sample of nitrogen gas is collected over water at 25°C and 1 atm. If the partial pressure of water vapor is 0.0313 atm, what is the mole \fraction of nitrogen gas?
A. 0.969
B. 0.971
C. 0.973
D. 0.975
Question 12
A solution contains 0.1 M NaCl and 0.1 M Na2SO4. What is the concentration of Cl^- ions in the solution?
A. 0.1 M
B. 0.15 M
C. 0.2 M
D. 0.25 M
Question 13
The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. What is the s\tandard enthalpy of formation of H2O(l) if the s\tandard enthalpy of formation of CO(g) is -110.5 kJ/mol and the s\tandard enthalpy of formation of H2(g) is 0 kJ/mol?
A. -285.8 kJ/mol
B. -285.9 kJ/mol
C. -286.0 kJ/mol
D. -286.1 kJ/mol
Question 14
A 1.00 M solution of H2SO4 is mixed with a 2.00 M solution of NaOH. What is the concentration of the resulting solution?
A. 1.00 M
B. 1.00 M
C. 1.00 M
D. 1.00 M
Question 15
The half-reaction for the reduction of Cr2O72- is: Cr2O72- + 14H+ + 6e- → 2Cr3+ + 7H2O. What is the s\tandard reduction potential of Cr2O72-?
A. +1.33 V
B. +1.33 V
C. +1.33 V
D. +1.33 V

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