POST UTME BELLS UNIVERSITY 2020 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
The rate cons\tant for a first-order reaction is 0.05 min^-1. What is the half-life of the reaction?
A. 10 min
B. 20 min
C. 30 min
D. 40 min
Question 2
A 100 mL sample of a solution containing 0.50 M NaCl is titrated with 0.10 M AgNO3. Calculate the volume of AgNO3 required to reach the equivalence point.
A. 50 mL
B. 100 mL
C. 150 mL
D. 200 mL
Question 3
The s\tandard enthalpy change of formation of carbon dioxide (CO2) is -393.5 kJ/mol. If 2.50 mol of CO2 is produced at 25°C, what is the total enthalpy change for the reaction?
A. -987.5 kJ
B. -1,225 kJ
C. -1,563 kJ
D. -1,875 kJ
Question 4
A 2.5 L flask contains 0.50 mol of an ideal gas at 298 K. Calculate the pressure of the gas u\sing the ideal gas law.
A. 1.01 x 10^2 kPa
B. 1.01 x 10^3 kPa
C. 1.01 x 10^4 kPa
D. 1.01 x 10^5 kPa
Question 5
Determine the s\tandard enthalpy of formation of CaCO3(s) from the following data: ΔHf(CaO(s)) = -635.09 kJ/mol, ΔHf(CO2(g)) = -393.51 kJ/mol.
A. -1206.60 kJ/mol
B. -1206.61 kJ/mol
C. -1206.59 kJ/mol
D. -1206.62 kJ/mol
Question 6
A metal (X) reacts with chlorine gas to form a white solid. The reaction is as follows: 2X + Cl2 → 2XCl. If 2.5 g of X reacts with 1.5 g of Cl2, what is the percentage yield of XCl?
A. 80%
B. 90%
C. 95%
D. 98%
Question 7
A diagram of a titration setup is shown below. If 25 mL of 0.1 M NaOH is added to 25 mL of 0.1 M HCl, what is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 8
The solubility of a slightly soluble salt, AgCl(s), in water at 298 K is 1.2 x 10^-5 mol/L. Calculate the molar solubility of AgCl(s) in a 0.10 M NaCl solution.
A. 1.2 x 10^-5 mol/L
B. 1.2 x 10^-4 mol/L
C. 1.2 x 10^-3 mol/L
D. 1.2 x 10^-2 mol/L
Question 9
The atomic radius of a certain element is 100 pm. If the element has an electron configuration of [Ar] 4s2 3d5, what is the expected oxidation state of the element?
A. +2
B. +3
C. +5
D. +7
Question 10
A 2.00 M solution of hydrochloric acid (HCl) is mixed with a 1.00 M solution of sodium hydroxide (NaOH). If 50.0 cm3 of the HCl solution is added to 50.0 cm3 of the NaOH solution, what is the concentration of the resulting solution?
A. 0.500 M
B. 1.00 M
C. 1.50 M
D. 2.00 M
Question 11
Determine the pH of a 0.1 M solution of HCl at 25°C.
A. 1
B. 2
C. 3
D. 4
Question 12
A diagram of a simple plant cell is shown below. Identify the part labeled A.
A. Chloroplast
B. Mitochondria
C. Nucleus
D. Vacuole
Question 13
Determine the pH of a 0.1 M solution of HCl.
A. 1
B. 2
C. 3
D. 4
Question 14
A 2.0 L flask contains 0.50 mol of an ideal gas at 298 K. Calculate the root mean square speed of the gas molecules.
A. 1.4 x 10^2 m/s
B. 1.4 x 10^3 m/s
C. 1.4 x 10^4 m/s
D. 1.4 x 10^5 m/s
Question 15
A sample of hydrogen gas (H2) is collected over water at 25°C and 1 atm. If the partial pressure of water vapor is 0.020 atm, what is the total pressure of the gas mixture?
A. 0.980 atm
B. 0.990 atm
C. 1.00 atm
D. 1.010 atm

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: