POST UTME UNIBEN 2024 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
The rate cons\tant for a first-order reaction is 0.05 min^-1. If the initial concentration of the reac\tant is 0.1 M, what is the concentration after 10 minutes?
A. 0.01 M
B. 0.05 M
C. 0.1 M
D. 0.2 M
Question 2
A cell consists of a zinc anode and a copper cathode. If the cell is connected to a 10 V power source, what is the current flowing through the cell?
A. 0.5 A
B. 1 A
C. 2 A
D. 5 A
Question 3
A 1.00 M solution of H2SO4 is titrated with 1.00 M NaOH. If 25.0 mL of NaOH is required to reach the equivalence point, what is the concentration of H2SO4?
A. 0.500 M
B. 0.750 M
C. 1.00 M
D. 1.25 M
Question 4
The reaction 2NO(g) + O2(g) → 2NO2(g) has a rate cons\tant of 1.50 × 10^\( -3 \) s^\( -1 \) at 298 K. What is the rate cons\tant at 323 K?
A. 2.50 × 10^\( -3 \) s^\( -1 \)
B. 3.00 × 10^\( -3 \) s^\( -1 \)
C. 3.50 × 10^\( -3 \) s^\( -1 \)
D. 4.00 × 10^\( -3 \) s^\( -1 \)
Question 5
A solution of 0.1 M HCl is mixed with a solution of 0.1 M NaOH. What is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 6
A solution of sodium chloride (NaCl) is prepared by dissolving 35.5 g of NaCl in 100 g of water at 25°C. Calculate the molality of the solution.
A. 0.25 mol/kg
B. 0.50 mol/kg
C. 0.75 mol/kg
D. 1.00 mol/kg
Question 7
A metal alloy is composed of 70% copper and 30% zinc. If 250g of the alloy is heated to 1000°C, calculate the amount of copper that will melt.
A. 120g
B. 150g
C. 180g
D. 200g
Question 8
The diagram below shows a titration setup. What is the purpose of the burette?
A. To measure the volume of the solution
B. To measure the concentration of the solution
C. To mix the solutions
D. To filter the solution
Question 9
A 2.50 M solution of HCl is titrated with 1.00 M NaOH. If 25.0 mL of NaOH is required to reach the equivalence point, what is the concentration of HCl?
A. 1.00 M
B. 1.25 M
C. 1.50 M
D. 2.00 M
Question 10
A 2.00 M solution of NaOH is prepared by dissolving 40.0 g of NaOH in 1.00 L of water. Calculate the pH of the solution.
A. 12.0
B. 13.0
C. 14.0
D. 15.0
Question 11
A sample of a polymer has a molecular weight of 50000 g/mol. If 2.5 g of the polymer is dissolved in 50 mL of a solvent, what is the concentration of the solution in g/L?
A. 0.05 g/L
B. 0.5 g/L
C. 5 g/L
D. 50 g/L
Question 12
The diagram below shows a titration setup. What is the purpose of the burette?
A. To measure the volume of the titrant
B. To measure the volume of the analyte
C. To mix the titrant and analyte
D. To heat the solution
Question 13
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, and ΔHf(C(s)) = 0 kJ/mol.
A. -1206.60 kJ/mol
B. -1206.19 kJ/mol
C. -1207.19 kJ/mol
D. -1207.60 kJ/mol
Question 14
A gas at 25°C and 1 atm is heated to 50°C at cons\tant pressure. What is the new volume of the gas?
A. 1.25 L
B. 1.5 L
C. 2 L
D. 2.5 L
Question 15
A solution of NaCl is prepared by dissolving 35 g of NaCl in 250 mL of water. What is the molarity of the solution?
A. 0.1 M
B. 0.5 M
C. 1 M
D. 2 M

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