POST UTME LAUTECH 2023 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 1.5 g sample of a metal M is heated in a stream of oxygen gas. If 1.0 g of the metal is converted to the oxide, what is the empirical formula of the oxide?
A. M2O3
B. M2O5
C. M3O4
D. M4O6
Question 2
What is the major environmental concern associated with the disposal of polychlorinated biphenyls (PCBs)?
A. Bioaccumulation
B. Bioavailability
C. Biodegradation
D. Bioconcentration
Question 3
A metal M reacts with chlorine gas to form a white solid. The reaction is as follows: M + Cl2 → MCl2. Which of the following metals could be M?
A. Magnesium
B. Calcium
C. Strontium
D. Barium
Question 4
A solution of sodium chloride (NaCl) is prepared by dissolving 35.5 g of NaCl in 100 mL of water. What is the molarity of the solution?
A. 0.1 M
B. 0.5 M
C. 1.0 M
D. 2.0 M
Question 5
What is the primary function of the enzyme chitinase in the degradation of chitin?
A. Hydrolysis
B. Oxidation
C. Reduction
D. Decarboxylation
Question 6
A 2.0 g sample of a non-metallic element is heated in a stream of oxygen gas. If 1.2 g of the element is converted to the oxide, what is the empirical formula of the oxide?
A. SO2
B. SO3
C. SO4
D. SO5
Question 7
The element with atomic number 12 is _______.
A. Mg
B. Ca
C. Sr
D. Ba
Question 8
A metal M reacts with oxygen gas to form a white solid. The reaction is as follows: 4M + 3O2 → 2M2O3. Which of the following metals could be M?
A. Magnesium
B. Calcium
C. Strontium
D. Barium
Question 9
The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. What is the s\tandard enthalpy of combustion of 1.00 mol of C(s) at 298 K?
A. -393.5 kJ/mol
B. -393.5 kJ/g
C. -393.5 kJ/mol C
D. -393.5 kJ/mol O2
Question 10
A 25.0 mL sample of 0.100 M HCl is titrated with 0.100 M NaOH. What is the pH of the solution after the addition of 15.0 mL of NaOH?
A. 2.00
B. 3.00
C. 4.00
D. 5.00
Question 11
The reaction of cyclopropane with chlorine gas in the presence of light produces a mixture of 1,2-dichlorocyclopropane and 1,3-dichlorocyclopropane. What is the major product of this reaction?
A. 1,2-dichlorocyclopropane
B. 1,3-dichlorocyclopropane
C. cis-1,2-dichlorocyclopropane
D. trans-1,2-dichlorocyclopropane
Question 12
A solution of sulfuric acid (H2SO4) is prepared by dissolving 98 g of H2SO4 in 100 mL of water. What is the concentration of the solution in terms of molality?
A. 1.0 m
B. 2.0 m
C. 3.0 m
D. 4.0 m
Question 13
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)?
A. -285.8 kJ/mol
B. -241.8 kJ/mol
C. -393.5 kJ/mol
D. -572.4 kJ/mol
Question 14
What is the primary purpose of the gas law PV=nRT?
A. To calculate the volume of a gas at cons\tant temperature
B. To calculate the pressure of a gas at cons\tant volume
C. To calculate the number of moles of a gas at cons\tant temperature
D. To calculate the temperature of a gas at cons\tant pressure
Question 15
What is the major difference between the structures of alkanes and alkenes?
A. Alkanes have a double bond, while alkenes have a \single bond
B. Alkanes have a \single bond, while alkenes have a double bond
C. Alkanes have a triple bond, while alkenes have a \single bond
D. Alkanes have a \single bond, while alkenes have a triple bond

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