POST UTME REDEEMERS UNIVERSITY 2023 Chemistry | Objective

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Question 1
A solution of HCl is titrated with a solution of NaOH. If 25 mL of the HCl solution requires 15 mL of the NaOH solution for neutralization, calculate the number of moles of HCl present in 1 L of the HCl solution.
A. 0.05 mol
B. 0.1 mol
C. 0.15 mol
D. 0.2 mol
Question 2
A 25.0-mL sample of a solution containing 0.100 M HCl is titrated with 0.100 M NaOH. What is the pH of the solution after the titration is complete?
A. 7.00
B. 8.00
C. 9.00
D. 10.0
Question 3
The rate cons\tant (k) for a first-order reaction is given by the equation: k = Ae^\( -Ea/RT \). If the activation energy (Ea) is 120 kJ/mol, the gas cons\tant (R) is 8.314 J/\( mol*K \), and the temperature (T) is 300 K, what is the value of the rate cons\tant (k) if the pre-exponential factor (A) is 1.0 x 10^10 s^\( -1 \)?
A. 1.0 x 10^\( -5 \) s^\( -1 \)
B. 1.0 x 10^\( -4 \) s^\( -1 \)
C. 1.0 x 10^\( -3 \) s^\( -1 \)
D. 1.0 x 10^\( -2 \) s^\( -1 \)
Question 4
A solution contains 0.500 M NaCl and 0.500 M KNO3. Calculate the molar solubility of Ba(NO3)2 in this solution.
A. 0.0100 M
B. 0.0200 M
C. 0.0300 M
D. 0.0400 M
Question 5
A 25.0 mL sample of a 0.10 M solution of NaOH is titrated with 0.10 M HCl. What is the pH of the solution after the titration?
A. 7.0
B. 8.0
C. 9.0
D. 10.0
Question 6
A solution of 0.100 M NaCl is prepared by dissolving 10.0 g of NaCl in 1.00 L of water. What is the concentration of Cl- ions in the solution?
A. 0.0500 M
B. 0.100 M
C. 0.200 M
D. 0.500 M
Question 7
The half-life of a radioactive subs\tance is 5 years. If 100 g of the subs\tance is initially present, how much will remain after 10 years?
A. 12.5 g
B. 25 g
C. 50 g
D. 100 g
Question 8
A sample of water contains 10 ppm of Cl- ions. What is the concentration of Cl- ions in mg/L?
A. 0.1 mg/L
B. 1 mg/L
C. 10 mg/L
D. 100 mg/L
Question 9
A 25.0 mL sample of 0.100 M HCl is titrated with 0.100 M NaOH. Calculate the pH of the solution after 15.0 mL of NaOH has been added.
A. 2.00
B. 2.50
C. 3.00
D. 3.50
Question 10
A 0.100 M solution of NaOH is titrated with 0.100 M HCl. If 25.0 mL of HCl is required to reach the equivalence point, what is the number of moles of NaOH present in the original solution?
A. 0.00250 mol
B. 0.00500 mol
C. 0.00750 mol
D. 0.0100 mol
Question 11
The reaction of cyclohexane with bromine in the presence of light produces a mixture of 1,2-dibromocyclohexane and 1,4-dibromocyclohexane. What is the major product of this reaction?
A. 1,2-dibromocyclohexane
B. 1,4-dibromocyclohexane
C. cis-1,2-dibromocyclohexane
D. trans-1,2-dibromocyclohexane
Question 12
A polymer, P, has a molecular weight of 100,000 g/mol. If 1 g of P is dissolved in 100 mL of water, calculate the concentration of P in g/L.
A. 1 g/L
B. 10 g/L
C. 100 g/L
D. 1000 g/L
Question 13
A 2.50 L flask contains 0.500 mol of an ideal gas at 25°C. What is the pressure of the gas?
A. 1.01 × 10^5 Pa
B. 2.01 × 10^5 Pa
C. 3.01 × 10^5 Pa
D. 4.01 × 10^5 Pa
Question 14
A 50.0 mL sample of 0.100 M H2SO4 is titrated with 0.100 M NaOH. Calculate the pH of the solution after 20.0 mL of NaOH has been added.
A. 1.00
B. 1.50
C. 2.00
D. 2.50
Question 15
A 0.1 M solution of H2SO4 is titrated with 0.1 M NaOH. What is the pH of the solution after 50 mL of NaOH has been added?
A. 1
B. 2
C. 3
D. 4

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