POST UTME UI 2023 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 100 mL sample of a solution containing 0.1 M HCl is titrated with 0.1 M NaOH. The pH of the solution is measured at various points during the titration. Plot a pH vs. volume of NaOH added curve. What is the pH of the solution at the equivalence point?
A. 7
B. 9
C. 10
D. 12
Question 2
A sample of a gas occupies 2.50 L at a pressure of 1.00 atm and a temperature of 25°C. What is the volume of the gas at a pressure of 2.00 atm and a temperature of 50°C?
A. 1.25 L
B. 2.50 L
C. 3.75 L
D. 5.00 L
Question 3
The s\tandard enthalpy of formation of carbon dioxide is -393.5 kJ/mol. What is the s\tandard enthalpy of formation of carbon monoxide?
A. -110.5 kJ/mol
B. -120.5 kJ/mol
C. -130.5 kJ/mol
D. -140.5 kJ/mol
Question 4
A 2.00 M solution of HCl is prepared by dissolving 40.0 g of HCl in 1.00 L of water. What is the concentration of the solution in molarity?
A. 1.00 M
B. 2.00 M
C. 3.00 M
D. 4.00 M
Question 5
The following diagram shows a titration setup for determining the concentration of a strong acid. What is the purpose of the burette in this setup?
A. To measure the volume of the acid
B. To measure the volume of the base
C. To mix the acid and base
D. To measure the pH of the solution
Question 6
A solution of 0.100 M HCl is titrated with 0.100 M NaOH. What is the pH of the solution after 25.0 mL of NaOH has been added?
A. 2.00
B. 3.00
C. 4.00
D. 5.00
Question 7
A 2.00 L flask contains 0.100 mol of N2 and 0.100 mol of O2 at 298 K. What is the partial pressure of N2?
A. 0.500 atm
B. 0.750 atm
C. 0.900 atm
D. 1.00 atm
Question 8
Determine the molar mass of a polymer with the following molecular formula: C10H8O4. Given that the molar mass of carbon is 12.01 g/mol, the molar mass of hydrogen is 1.008 g/mol, and the molar mass of oxygen is 16.00 g/mol.
A. 288.16 g/mol
B. 296.16 g/mol
C. 304.16 g/mol
D. 312.16 g/mol
Question 9
Determine the pH of a 0.1 M solution of HCl after 25 mL of 0.1 M NaOH has been added to 25 mL of the HCl solution. The reaction is carried out in a 100 mL flask.
A. 1
B. 2
C. 3
D. 4
Question 10
A 0.500 M solution of HCl is titrated with 0.500 M NaOH. Calculate the number of moles of HCl that have reacted after 25.0 mL of NaOH has been added.
A. 0.0125 mol
B. 0.0125 mol
C. 0.0125 mol
D. 0.0125 mol
Question 11
A 0.500 M solution of NaOH is prepared by dissolving 25.0 g of NaOH in 1.00 L of water. What is the concentration of the solution in molarity?
A. 0.500 M
B. 0.750 M
C. 1.00 M
D. 1.25 M
Question 12
The reaction between CH3OH(l) and HCl(g) is catalyzed by H2SO4(s). Write the balanced equation for the reaction.
A. CH3OH(l) + HCl(g) → CH3Cl(g) + H2O(l)
B. CH3OH(l) + HCl(g) → CH3Cl(g) + H2O(l)
C. CH3OH(l) + HCl(g) → CH3Cl(g) + H2O(l)
D. CH3OH(l) + HCl(g) → CH3Cl(g) + H2O(l)
Question 13
The reaction of ethanol with oxygen in the presence of a catalyst is an example of a combustion reaction. The balanced chemical equation for this reaction is: \( C_2H_5OH + 3O_2 \rightarrow 2CO_2 + 3H_2O \). What is the mole ratio of ethanol to oxygen in this reaction?
A. 1:1
B. 1:2
C. 1:3
D. 2:3
Question 14
The atomic radius of an atom is defined as the dis\tance from the nucleus to the outermost electron in a neutral atom. Which of the following statements is NOT true about atomic radius?
A. Atomic radius decreases as the atomic number increases.
B. Atomic radius increases as the atomic number increases.
C. Atomic radius is the same for all isotopes of an element.
D. Atomic radius is the dis\tance from the nucleus to the outermost electron in a neutral atom.
Question 15
A 2.5 L sample of oxygen gas at 25°C and 1 atm is collected over water. What is the partial pressure of oxygen gas in the sample?
A. 0.5 atm
B. 0.75 atm
C. 1 atm
D. 1.25 atm

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