POST UTME BSU 2023 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
The reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl) is highly exothermic. Calculate the s\tandard enthalpy change \( ΔH^circ \) for the reaction, given that the s\tandard enthalpy of formation \( ΔH^circ_f \) for NaOH is -469 kJ/mol and for HCl is -92 kJ/mol.
A. -581 kJ/mol
B. -469 kJ/mol
C. -92 kJ/mol
D. 581 kJ/mol
Question 2
A 2.5 L sample of a gas at 27°C and 1.2 atm is compressed to 0.5 L at 37°C. Calculate the final pressure of the gas.
A. 2.5 atm
B. 3.2 atm
C. 4.1 atm
D. 5.5 atm
Question 3
The diagram below shows a setup for the electrolysis of water. What is the purpose of the U-tube containing mercury?
A. To collect the hydrogen gas produced at the cathode
B. To collect the oxygen gas produced at the anode
C. To prevent the water from boiling during electrolysis
D. To act as a catalyst for the reaction
Question 4
A 2.0 M solution of H2SO4 is mixed with a 2.0 M solution of NaOH. What is the concentration of the resulting solution?
A. 1.0 M
B. 2.0 M
C. 3.0 M
D. 4.0 M
Question 5
A 2.0 L sample of a gas at 25°C and 1 atm is collected over water at 25°C. If the vapor pressure of water at 25°C is 23.8 mmHg, calculate the partial pressure of the gas.
A. 760 mmHg
B. 736 mmHg
C. 712 mmHg
D. 688 mmHg
Question 6
A 1.0 L flask contains 0.1 mol of CO2 at 298 K. What is the partial pressure of CO2 in the flask?
A. 101.3 kPa
B. 50.65 kPa
C. 25.33 kPa
D. 12.67 kPa
Question 7
A metal oxide has the formula MO2. What is the oxidation state of the metal?
A. +2
B. +3
C. +4
D. +5
Question 8
A solution contains 10 g of sodium hydroxide (NaOH) dissolved in 100 g of water. What is the molality of the solution?
A. 0.1 m
B. 0.2 m
C. 0.3 m
D. 0.4 m
Question 9
A metal reacts with oxygen to form a basic oxide. Which of the following metals is most likely to form a basic oxide?
A. Magnesium (Mg)
B. Calcium (Ca)
C. Strontium (Sr)
D. Barium (Ba)
Question 10
A diagram of a gas law setup is shown below. The pressure of the gas is 101.3 kPa, and the volume is 1.0 L. What is the temperature of the gas in Kelvin?
A. 298 K
B. 273 K
C. 373 K
D. 473 K
Question 11
A solution contains 0.100 M NaCl. If 25.0 mL of this solution is diluted to 250 mL, what is the concentration of the resulting solution?
A. 0.010 M
B. 0.050 M
C. 0.100 M
D. 0.200 M
Question 12
A 1.0 M solution of sodium hydroxide (NaOH) is prepared by dissolving 40 g of NaOH in 1 L of water. Calculate the pH of the solution.
A. 13
B. 14
C. 15
D. 16
Question 13
A solution contains 5 g of sodium chloride (NaCl) dissolved in 100 g of water. What is the molality of the solution?
A. 0.05 m
B. 0.1 m
C. 0.15 m
D. 0.2 m
Question 14
A sample of a polymer has a molecular weight of 100,000 g/mol. If the polymer is composed of 80% by mass of carbon (C) and 20% by mass of hydrogen (H), calculate the number of moles of carbon atoms in the polymer.
A. 8.0 x 10^22
B. 8.0 x 10^23
C. 8.0 x 10^24
D. 8.0 x 10^25
Question 15
A 1.0 M solution of H2SO4 is mixed with a 2.0 M solution of NaOH. What is the resulting concentration of the solution?
A. 1.0 M
B. 1.5 M
C. 2.0 M
D. 2.5 M

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Help others prepare! Share this practice hub: