POST UTME NOUN 2021 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
Determine the s\tandard enthalpy of formation of NO2(g) from the following data: ΔH°f(N2(g)) = 0 kJ/mol, ΔH°f(O2(g)) = 0 kJ/mol, ΔH°f(NO(g)) = 90.29 kJ/mol. The reaction is: N2(g) + 2O2(g) → 2NO2(g).
A. -99.41 kJ/mol
B. -90.29 kJ/mol
C. -80.29 kJ/mol
D. -70.29 kJ/mol
Question 2
A solution contains 0.10 M NaCl. What is the concentration of Cl- ions in the solution?
A. 0.05 M
B. 0.10 M
C. 0.15 M
D. 0.20 M
Question 3
A metal reacts with oxygen to form a basic oxide. What is the type of reaction?
A. Combustion reaction
B. Neutralization reaction
C. Oxidation-reduction reaction
D. Synthesis reaction
Question 4
Calculate the s\tandard enthalpy change for the reaction: 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s).
A. -850 kJ/mol
B. -1000 kJ/mol
C. -1200 kJ/mol
D. -1500 kJ/mol
Question 5
A metal (X) reacts with dilute hydrochloric acid to produce a gas (Y). The gas (Y) is used in the manufacture of semiconductors. Identify the metal (X) and the gas (Y).
A. Zinc, Hydrogen
B. Iron, Oxygen
C. Copper, Nitrogen
D. Lead, Carbon Dioxide
Question 6
A sample of a non-metal (X) has a mass of 2.5 g. The sample is heated in a crucible until it reaches a temperature of 2500 K. The resulting gas (Y) is collected and its volume is measured to be 2.5 L at a pressure of 1 atm. Identify the non-metal (X) and the gas (Y).
A. Sulfur, Sulfur Dioxide
B. Phosphorus, Phosphorus Pentoxide
C. Carbon, Carbon Monoxide
D. Nitrogen, Nitrogen Gas
Question 7
A 1.0 L flask contains 0.5 mol of an ideal gas at 298 K. If the volume of the flask is doubled, what is the new pressure of the gas?
A. 1.0 atm
B. 1.5 atm
C. 2.0 atm
D. 2.5 atm
Question 8
A 0.5 M solution of CuSO4 is electrolyzed u\sing a platinum electrode. If the cell potential is 1.0 V, what is the mass of Cu produced at the cathode in 1 hour?
A. 0.1 g
B. 0.2 g
C. 0.3 g
D. 0.4 g
Question 9
A 2.0 M solution of NaOH is electrolyzed u\sing a platinum electrode. If the cell potential is 2.5 V, what is the mass of H2 gas produced at the cathode in 2 hours?
A. 1.0 g
B. 2.0 g
C. 3.0 g
D. 4.0 g
Question 10
A 2.0 M solution of HCl is mixed with a 1.0 M solution of NaOH. If 50.0 mL of the HCl solution is added to 100.0 mL of the NaOH solution, what is the pH of the resulting solution?
A. 1.0
B. 2.0
C. 3.0
D. 4.0
Question 11
A solution contains 2.5 g of NaCl in 100 mL of water. What is the molarity of the solution?
A. 0.25 M
B. 0.5 M
C. 1.0 M
D. 2.0 M
Question 12
A sample of a polymer has a molecular weight of 100,000 g/mol. If the polymer is composed of 80% monomer A and 20% monomer B, what is the average molecular weight of the polymer?
A. 80,000 g/mol
B. 90,000 g/mol
C. 100,000 g/mol
D. 110,000 g/mol
Question 13
Determine the pH of a solution containing 0.1 M HCl and 0.1 M NaOH.
A. 1
B. 2
C. 7
D. 14
Question 14
What is the primary function of a catalyst in a chemical reaction?
A. To increase the reaction rate
B. To decrease the reaction rate
C. To change the reaction pathway
D. To inhibit the reaction
Question 15
A sample of a polymer has a molecular weight of 100,000 g/mol. If the polymer is composed of 80% monomer A and 20% monomer B, what is the average molecular weight of the polymer?
A. 80,000 g/mol
B. 90,000 g/mol
C. 100,000 g/mol
D. 110,000 g/mol

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