POST UTME LEAD CITY UNIVERSITY 2023 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
The reaction: 2NO(g) + O2(g) → 2NO2(g) has a rate cons\tant (k) of 1.5 × 10^\( -2 \) s^\( -1 \) at 298 K. If the activation energy (Ea) is 2.5 × 10^5 J/mol, what is the rate cons\tant (k) at 308 K?
A. 2.0 × 10^\( -2 \) s^\( -1 \)
B. 2.5 × 10^\( -2 \) s^\( -1 \)
C. 3.0 × 10^\( -2 \) s^\( -1 \)
D. 3.5 × 10^\( -2 \) s^\( -1 \)
Question 2
A solution containing 0.1 M NaOH is electrolyzed u\sing a current of 0.5 A for 2 hours. Calculate the mass of O2 gas produced at the cathode.
A. 0.1 g
B. 0.2 g
C. 0.3 g
D. 0.4 g
Question 3
A 2.5 M solution of H2SO4 is prepared by dissolving 2.5 g of H2SO4 in 100 mL of water. What is the mass of H2SO4 required to prepare a 1.0 M solution?
A. 1.0 g
B. 1.5 g
C. 2.0 g
D. 2.5 g
Question 4
A solution of 0.1 M NaOH is mixed with a solution of 0.1 M HCl. What is the pH of the resulting solution?
A. 1
B. 2
C. 7
D. 14
Question 5
The reaction between sodium hydroxide and acetic acid is represented by the equation: CH3COOH + NaOH → CH3COONa + H2O. If 25.0 mL of 0.500 M acetic acid is mixed with 25.0 mL of 0.500 M sodium hydroxide, what is the limiting reac\tant?
A. Acetic acid
B. Sodium hydroxide
C. Water
D. Sodium acetate
Question 6
A diagram of a titration setup is shown below. The burette contains 0.1 M NaOH, and the flask contains 25 mL of 0.1 M HCl. What is the pH of the resulting solution after the titration?
A. 1
B. 2
C. 7
D. 14
Question 7
A 2.00 L flask contains 0.500 mol of an ideal gas at 298 K. If the gas is compressed to 1.00 L, what is the new pressure?
A. 1.00 atm
B. 1.00 atm
C. 1.00 atm
D. 1.00 atm
Question 8
The s\tandard enthalpy of formation of CO(g) is -110.5 kJ/mol. Calculate the s\tandard enthalpy of combustion of 1.5 mol of C(s) to form CO(g).
A. -165.75 kJ
B. -166.25 kJ
C. -166.75 kJ
D. -167.25 kJ
Question 9
A 0.1 M solution of a monoprotic acid is titrated with 0.1 M NaOH. If 25 mL of the acid is titrated with 15 mL of the base, what is the pH of the resulting solution?
A. 3
B. 4
C. 5
D. 6
Question 10
A solution containing 0.1 M NaCl is electrolyzed u\sing a current of 0.5 A for 2 hours. Calculate the mass of Cl2 gas produced at the anode.
A. 0.1 g
B. 0.2 g
C. 0.3 g
D. 0.4 g
Question 11
The s\tandard enthalpy of formation of H2O(l) is -285.8 kJ/mol. Calculate the s\tandard enthalpy of vaporization of 1 mol of H2O(l) to form H2O(g).
A. -44.0 kJ
B. -44.5 kJ
C. -45.0 kJ
D. -45.5 kJ
Question 12
A 0.500 L solution contains 0.100 M NaCl. What is the concentration of Cl- ions?
A. 0.0500 M
B. 0.0500 M
C. 0.0500 M
D. 0.0500 M
Question 13
A 0.1 M solution of a weak base B is titrated with 0.1 M HCl. If 20 mL of the base solution requires 15 mL of HCl for neutralization, calculate the number of moles of B in 1 L of the base solution.
A. 0.01 mol
B. 0.02 mol
C. 0.03 mol
D. 0.04 mol
Question 14
A 2.50 L flask contains 0.500 mol of an ideal gas at 298 K. If 0.250 mol of the gas is removed, what is the new pressure?
A. 0.500 atm
B. 0.500 atm
C. 0.500 atm
D. 0.500 atm
Question 15
A 0.1 M solution of a weak acid is titrated with 0.1 M NaOH. If 20 mL of the acid is titrated with 10 mL of the base, what is the pH of the resulting solution?
A. 2
B. 3
C. 4
D. 5

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