POST UTME BSU 2024 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 1.0 M solution of a weak base, B, is titrated with 1.0 M HCl. If the initial pH of the base is 10.5, what is the pH at the equivalence point?
A. 3.5
B. 5.5
C. 7.5
D. 9.5
Question 2
A 1.0 M solution of a strong acid, HA, is titrated with 1.0 M NaOH. If the initial pH of the acid is 2.5, what is the pH at the equivalence point?
A. 7.5
B. 9.5
C. 11.5
D. 13.5
Question 3
The half-life of a radioactive subs\tance is 5 years. If the initial amount of the subs\tance is 100 g, how much of the subs\tance will remain after 10 years?
A. 50 g
B. 50 g
C. 50 g
D. 50 g
Question 4
A solution of 0.1 M HCl is titrated with a solution of 0.1 M NaOH. What is the pH of the solution after 20 mL of NaOH has been added?
A. 2
B. 4
C. 6
D. 8
Question 5
A metal M reacts with oxygen to form a basic oxide MO. If 2.5 g of M reacts with 1.5 g of O2 to form 3.5 g of MO, what is the percentage of M in MO?
A. 40%
B. 40%
C. 40%
D. 40%
Question 6
A 0.5 M solution of a weak acid, HA, is titrated with 0.5 M NaOH. If the initial pH of the acid is 3.5, what is the pH at the equivalence point?
A. 7.5
B. 9.5
C. 11.5
D. 13.5
Question 7
The half-life of a radioactive subs\tance is 10 years. If 100 g of the subs\tance is initially present, how much of the subs\tance will remain after 20 years?
A. 25 g
B. 50 g
C. 75 g
D. 100 g
Question 8
A 25 mL sample of a 0.5 M solution of NaOH is titrated with 0.1 M HCl. Calculate the number of moles of HCl required to reach the equivalence point.
A. 0.0125
B. 0.025
C. 0.0375
D. 0.05
Question 9
A polymer has a molecular weight of 5000 g/mol and a degree of polymerization of 100. What is the molar mass of the repeating unit?
A. 50 g/mol
B. 100 g/mol
C. 500 g/mol
D. 1000 g/mol
Question 10
A 2.0 M solution of HCl is prepared by dissolving 40 g of HCl in 100 mL of water. What is the concentration of the solution in g/L?
A. 40 g/L
B. 400 g/L
C. 4000 g/L
D. 40000 g/L
Question 11
The diagram below shows a titration setup. If the burette contains 0.1 M NaOH and the initial volume is 25 mL, what is the concentration of the HCl solution if 10 mL of NaOH is required to reach the equivalence point?
A. 0.05 M
B. 0.1 M
C. 0.2 M
D. 0.5 M
Question 12
The rate cons\tant (k) of a first-order reaction is given by the equation: k = Ae^\( -Ea/RT \). If the activation energy (Ea) is 100 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 10^6 s^-1
B. 1.0 x 10^7 s^-1
C. 1.0 x 10^8 s^-1
D. 1.0 x 10^9 s^-1
Question 13
A 1.0 L sample of a solution containing 0.1 M HCl and 0.1 M NaOH is titrated with a solution of 0.1 M H2SO4. What is the pH of the solution after 20 mL of H2SO4 has been added?
A. 2
B. 4
C. 6
D. 8
Question 14
A 2.0 g sample of a metal is electrolyzed in a solution of 1.0 M H2SO4. What is the mass of the metal deposited at the cathode?
A. 1.0 g
B. 2.0 g
C. 3.0 g
D. 4.0 g
Question 15
A 2.5 g sample of a non-metallic oxide is heated in a stream of CO gas. If 1.2 g of CO is consumed, calculate the empirical formula of the oxide.
A. MgO
B. CaO
C. SiO2
D. Al2O3

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