POST UTME PAN-ATLANTIC UNIVERSITY 2025 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A metal (M) has an atomic radius of 200 pm. If the metal forms a +2 ion, what is the radius of the ion?
A. 100 pm
B. 150 pm
C. 200 pm
D. 250 pm
Question 2
A 2.50 g sample of a compound containing only C, H, and O is analyzed by combustion. The CO2 produced is collected and found to have a mass of 1.25 g. The H2O produced is collected and found to have a mass of 0.500 g. What is the empirical formula of the compound?
A. C2H4O2
B. C2H6O
C. C3H6O
D. C3H8O
Question 3
The rate cons\tant for the decomposition of a certain compound is 2.50 × 10⁻² s⁻¹ at 25°C. If the initial concentration of the compound is 0.100 M, calculate the concentration of the compound after 5.00 minutes.
A. 0.0500 M
B. 0.0750 M
C. 0.100 M
D. 0.125 M
Question 4
A 2.50-g sample of a polymer is dissolved in 100 mL of a solvent. The osmotic pressure of the solution is measured to be 1.20 atm at 25°C. Calculate the molar mass of the polymer.
A. 1000 g/mol
B. 2000 g/mol
C. 5000 g/mol
D. 10,000 g/mol
Question 5
A metal (M) has an atomic radius of 250 pm. If the metal forms a +3 ion, what is the radius of the ion?
A. 80 pm
B. 100 pm
C. 120 pm
D. 150 pm
Question 6
The reaction of 1-bu\tanol with concentrated sulfuric acid produces a mixture of butyl hydrogen sulfate and butyl sulfate. Write the balanced chemical equation for this reaction.
A. CH₃CH₂CH₂CH₂OH + H₂SO₄ → CH₃CH₂CH₂CH₂OSO₃H + H₂O
B. CH₃CH₂CH₂CH₂OH + H₂SO₄ → CH₃CH₂CH₂CH₂OSO₃H + CH₃CH₂CH₂CH₂OH
C. CH₃CH₂CH₂CH₂OH + H₂SO₄ → CH₃CH₂CH₂CH₂OSO₃H + CH₃CH₂CH₂CH₂OSO₃H
D. CH₃CH₂CH₂CH₂OH + H₂SO₄ → CH₃CH₂CH₂CH₂OSO₃H + CH₃CH₂CH₂CH₂OH + H₂O
Question 7
A 25.0 mL sample of 0.150 M HCl is mixed with a 25.0 mL sample of 0.150 M NaOH. What is the concentration of the resulting solution?
A. 0.0750 M
B. 0.150 M
C. 0.225 M
D. 0.300 M
Question 8
A 2.00 g sample of a subs\tance is burned in a bomb calorimeter. The temperature of the calorimeter increases by 10.0 K. What is the heat of combustion of the subs\tance?
A. \Delta H = -20.0 kJ
B. \Delta H = -30.0 kJ
C. \Delta H = -40.0 kJ
D. \Delta H = -50.0 kJ
Question 9
A sample of oxygen (O2) is collected over water at a temperature of 20°C and a pressure of 1 atm. What is the volume of the gas at STP?
A. 2.0 L
B. 2.5 L
C. 3.0 L
D. 3.5 L
Question 10
A 2.50 L flask contains 0.500 mol of an ideal gas at 298 K. Calculate the pressure of the gas u\sing the ideal gas law.
A. P = 1.01 × 10^5 Pa
B. P = 2.01 × 10^5 Pa
C. P = 3.01 × 10^5 Pa
D. P = 4.01 × 10^5 Pa
Question 11
A 0.500 M solution of H2SO4 is titrated with 0.500 M NaOH. What is the pH of the solution after 25.0 mL of NaOH has been added?
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 12
A solution of hydrochloric acid (HCl) is prepared by dissolving 25 g of the acid in 250 mL of water. What is the concentration of the solution in g/L?
A. 100 g/L
B. 110 g/L
C. 120 g/L
D. 130 g/L
Question 13
A solution of sodium chloride (NaCl) is prepared by dissolving 35 g of the salt in 250 mL of water. What is the concentration of the solution in g/L?
A. 140 g/L
B. 150 g/L
C. 160 g/L
D. 170 g/L
Question 14
A 1.00 M solution of NaOH is titrated with 1.00 M HCl. What is the pH of the solution after 50.0 mL of HCl has been added?
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 15
A 1.00 M solution of NaOH is mixed with a 1.00 M solution of HCl. What is the concentration of the resulting solution?
A. C = 1.00 M
B. C = 2.00 M
C. C = 3.00 M
D. C = 4.00 M

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Help others prepare! Share this practice hub: