POST UTME ESUT 2025 Chemistry | Objective

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Question 1
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. 20 g/L
B. 50 g/L
C. 100 g/L
D. 200 g/L
Question 2
A 1.5 g sample of a metal chloride (MCl2) is dissolved in 20 mL of water. If the resulting solution has a conductivity of 0.25 S/m, what is the molar conductivity of the solution?
A. 0.5 S m^2/mol
B. 1 S m^2/mol
C. 2 S m^2/mol
D. 5 S m^2/mol
Question 3
Determine the number of moles of acetic acid (CH3COOH) that can be obtained from 250 mL of a 0.5 M solution of sodium acetate (CH3COONa) in water, assuming that the reaction is 100% efficient.
A. 0.125 mol
B. 0.25 mol
C. 0.5 mol
D. 1 mol
Question 4
A 25.0 mL sample of 0.100 M HCl is added to a 50.0 mL sample of 0.100 M NaOH. What is the concentration of the resulting solution?
A. 0.0500 M
B. 0.0501 M
C. 0.0502 M
D. 0.0503 M
Question 5
A sample of a gas has a volume of 2 L at a pressure of 1 atm and a temperature of 300 K. What is the volume of the gas at a pressure of 2 atm and a temperature of 400 K?
A. 1 L
B. 2 L
C. 3 L
D. 4 L
Question 6
A solution contains 0.50 M NaCl and 0.25 M CaCl2. What is the concentration of Cl- ions in the solution?
A. 0.375 M
B. 0.500 M
C. 0.625 M
D. 0.750 M
Question 7
The reaction of sodium (Na) with water (H2O) is highly exothermic. What is the primary product of this reaction?
A. Sodium hydroxide (NaOH)
B. Sodium chloride (NaCl)
C. Hydrogen gas (H2)
D. Sodium oxide (Na2O)
Question 8
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 H2(g) is 0 kJ/mol and that of O2(g) is 0 kJ/mol?
A. -285.8 kJ/mol
B. -241.8 kJ/mol
C. -393.5 kJ/mol
D. -572.8 kJ/mol
Question 9
A redox reaction involves the transfer of electrons from a reducing agent to an oxidizing agent. What is the primary function of the reducing agent in this reaction?
A. To accept electrons
B. To donate electrons
C. To facilitate the reaction
D. To inhibit the reaction
Question 10
A reaction is first-order with respect to the reac\tant A. If the initial concentration of A is 0.1 M and the rate cons\tant is 0.01 min^-1, what is the concentration of A after 10 min?
A. 0.05 M
B. 0.1 M
C. 0.15 M
D. 0.2 M
Question 11
The reaction between nitrogen dioxide and water is represented by the equation: 3NO2 + H2O → 2HNO3 + NO. If 2.5 g of NO2 is reacted with excess water, calculate the number of moles of HNO3 produced.
A. 0.25 mol
B. 0.5 mol
C. 0.75 mol
D. 1.0 mol
Question 12
A solution of a monosaccharide (C6H12O6) is titrated with a solution of NaOH. If 25 mL of the monosaccharide solution requires 15 mL of 0.5 M NaOH to reach the equivalence point, what is the molar mass of the monosaccharide?
A. 180 g/mol
B. 200 g/mol
C. 220 g/mol
D. 240 g/mol
Question 13
A mixture of 2.0 g of NaCl and 1.0 g of KCl is dissolved in 100 mL of water. What is the molarity of the solution?
A. 0.1 M
B. 0.2 M
C. 0.3 M
D. 0.4 M
Question 14
A 2.00 g sample of a metal is heated in a crucible to produce a 1.50 g sample of the metal oxide. What is the percentage yield of the metal oxide?
A. 75%
B. 80%
C. 85%
D. 90%
Question 15
The reaction of sodium carbonate with hydrochloric acid yields sodium chloride, water, and carbon dioxide gas. What is the balanced chemical equation for this reaction?
A. \( Na_2CO_3 \( aq \ \) + HCl (aq) \rightarrow NaCl (aq) + H_2O (l) + CO (g) )
B. \( Na_2CO_3 \( aq \ \) + 2HCl (aq) \rightarrow 2NaCl (aq) + H_2O (l) + CO_2 (g) )
C. \( Na_2CO_3 \( aq \ \) + HCl (aq) \rightarrow NaCl (aq) + H_2O (l) + CO_2 (g) )
D. \( Na_2CO_3 \( aq \ \) + 2HCl (aq) \rightarrow 2NaCl (aq) + H_2O (l) + CO (g) )

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