POST UTME LAUTECH 2022 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 2.0 L sample of a gas at 25°C and 1 atm is compressed to 0.5 L at 50°C. What is the final pressure of the gas in atm?
A. 2 atm
B. 4 atm
C. 6 atm
D. 8 atm
Question 2
A solution of 0.1 M NaCl is prepared by dissolving 6.0 g of NaCl in 100 mL of water. What is the concentration of the solution in g/L?
A. 0.6 g/L
B. 1.2 g/L
C. 1.8 g/L
D. 2.4 g/L
Question 3
A metal (M) reacts with oxygen to form a basic oxide. The reaction is: 4M + 3O2 → 2MO3. If 2.5 g of M reacts with 3.5 g of O2, calculate the percentage yield of MO3.
A. 80%
B. 90%
C. 95%
D. 98%
Question 4
Determine the molar solubility of AgCl in a 0.1 M NaCl solution, given that the solubility product cons\tant (Ksp) of AgCl is 1.8 × 10^-10.
A. 1.0 × 10^-5 M
B. 1.5 × 10^-5 M
C. 2.0 × 10^-5 M
D. 3.0 × 10^-5 M
Question 5
A 0.1 M solution of NaOH is prepared by dissolving 2.0 g of NaOH in 100 mL of water. What is the concentration of NaOH in the solution in units of mol/L?
A. 0.02 M
B. 0.04 M
C. 0.06 M
D. 0.08 M
Question 6
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 HCl in the solution in units of mol/L?
A. 1.0 M
B. 2.0 M
C. 3.0 M
D. 4.0 M
Question 7
A sample of an ideal gas at 25°C and 1 atm is heated to 50°C at cons\tant volume. What is the final pressure of the gas in atm?
A. 1.5 atm
B. 2 atm
C. 3 atm
D. 4 atm
Question 8
The compound with the molecular formula C4H10 is a branched alkane. Draw the structure of this compound.
A. CH3CH2CH2CH3
B. CH3CH2CH(CH3)2
C. CH3CH(CH3)CH2CH3
D. CH3C(CH3)2CH2CH3
Question 9
A 0.1 M solution of a weak acid HA is mixed with 0.1 M NaOH. If the initial pH of the acid is 3, calculate the pH after 10 minutes.
A. 4
B. 5
C. 6
D. 7
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 25.0 mL of NaOH?
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 11
A 10.0 g sample of a non-metallic oxide is heated in a crucible. The mass of the oxide decreases by 2.50 g. What is the percentage decrease in mass?
A. 12.5%
B. 25.0%
C. 37.5%
D. 50.0%
Question 12
The half-life of a radioactive subs\tance is 5 years. If the initial activity is 1000 Bq, calculate the activity after 10 years.
A. 125 Bq
B. 250 Bq
C. 500 Bq
D. 1000 Bq
Question 13
The rate cons\tant of a reaction is given by the equation: k = Ae^\( -Ea/RT \). If the rate cons\tant at 25°C is 0.05 s^\( -1 \) and at 50°C is 0.15 s^\( -1 \), calculate the activation energy (Ea) of the reaction in kJ/mol.
A. 20 kJ/mol
B. 30 kJ/mol
C. 40 kJ/mol
D. 50 kJ/mol
Question 14
A 2.5 g sample of sulfur is burned in oxygen to form sulfur dioxide. If the reaction is complete, what is the volume of sulfur dioxide produced at STP?
A. 1.2 L
B. 2.4 L
C. 3.6 L
D. 4.8 L
Question 15
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-1,4-dibromocyclohexane

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