POST UTME PAN-ATLANTIC UNIVERSITY 2021 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 2.5 g sample of a non-metallic oxide is found to contain 0.625 g of oxygen. What is the empirical formula of the oxide?
A. O2S
B. SO2
C. SO3
D. S2O3
Question 2
A 2.00 L flask contains 1.00 M H2(g) at 298 K. If 1.00 mol of O2(g) is added to the flask, what is the new equilibrium concentration of H2(g)?
A. 0.500 M
B. 0.750 M
C. 1.00 M
D. 1.25 M
Question 3
A polymer has a molecular weight of 100,000 g/mol and a degree of polymerization of 500. What is the molar mass of the monomer?
A. 200 g/mol
B. 500 g/mol
C. 1000 g/mol
D. 2000 g/mol
Question 4
A 2.0 L flask contains 0.5 mol of CO2 at 25°C. What is the partial pressure of CO2 in the flask?
A. 0.25 atm
B. 0.50 atm
C. 0.75 atm
D. 1.00 atm
Question 5
A 0.500 M solution of NaOH is titrated with 0.500 M HCl. What is the pH of the solution after the reaction is complete?
A. 7.00
B. 7.50
C. 8.00
D. 9.00
Question 6
A 0.100 M solution of NaOH is mixed with 0.100 M solution of HCl. If the reaction is allowed to go to completion, what is the pH of the resulting solution?
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 7
A diagram of a cell is shown below. What is the function of the mitochondria in this cell?
A. To synthesize proteins
B. To generate energy for the cell
C. To store genetic information
D. To regulate cell growth
Question 8
A 0.5 M solution of HCl is prepared by dissolving 50 g of HCl in 100 mL of water. What is the concentration of HCl in the solution, expressed in g/L?
A. 0.25 g/L
B. 0.50 g/L
C. 0.75 g/L
D. 1.00 g/L
Question 9
The reaction of nitrogen with oxygen to form nitrogen dioxide is represented by the equation: 4NO + O2 → 2NO2. What is the oxidation state of nitrogen in NO2?
A. +2
B. +3
C. +4
D. +5
Question 10
Determine the number of moles of ethene gas (C2H4) that can be produced from 2.5 moles of ethyne gas (C2H2) according to the reaction: 2C2H2(g) → 2C2H4(g) + H2(g).
A. 1.25 moles
B. 2.5 moles
C. 3.75 moles
D. 5 moles
Question 11
The s\tandard reduction potential of the couple Zn2+/Zn is -0.76 V. If a zinc electrode is connected to a copper electrode with a s\tandard reduction potential of +0.34 V, what is the cell potential (Ecell) of the cell?
A. -1.10 V
B. -0.90 V
C. -0.76 V
D. +0.34 V
Question 12
A 0.2 M solution of glu\cose (C6H12O6) is prepared by dissolving 12 g of glu\cose in 100 mL of water. What is the concentration of glu\cose in the solution, expressed in g/L?
A. 0.12 g/L
B. 0.24 g/L
C. 0.36 g/L
D. 0.48 g/L
Question 13
The half-life of a radioactive subs\tance is 5.00 years. If 100.0 g of the subs\tance is present initially, how much will remain after 20.0 years?
A. 25.0 g
B. 50.0 g
C. 75.0 g
D. 100.0 g
Question 14
The s\tandard Gibbs free energy change (ΔG°) for the reaction 2NO(g) + O2(g) → 2NO2(g) at 298 K and 1 atm is -111.3 kJ/mol. Calculate the equilibrium cons\tant (K) for this reaction.
A. 1.00 × 10^5
B. 1.00 × 10^3
C. 1.00 × 10^2
D. 1.00 × 10^1
Question 15
The reaction of sodium with water is a classic example of a redox reaction. What is the product formed when sodium reacts with water?
A. Sodium hydroxide and hydrogen gas
B. Sodium oxide and water
C. Sodium hydroxide and sodium oxide
D. Hydrogen gas and sodium oxide

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: