POST UTME EKSU 2025 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 2.0 M solution of hydrochloric acid (HCl) is prepared by dissolving 80 g of HCl in water to make 1 L of solution. Calculate the molarity of the solution.
A. 1.0 M
B. 2.0 M
C. 2.5 M
D. 3.0 M
Question 2
A 2.5 g sample of a metal carbonate is heated to produce a metal oxide and carbon dioxide gas. If the mass of the metal oxide produced is 1.8 g, what is the percentage yield of the reaction?
A. 50%
B. 60%
C. 70%
D. 80%
Question 3
A 2.5 M solution of sulfuric acid (H2SO4) is prepared by dissolving 125 g of H2SO4 in water to make 1 L of solution. Calculate the molarity of the solution.
A. 1.0 M
B. 2.0 M
C. 2.5 M
D. 5.0 M
Question 4
Determine the number of moles of carbon dioxide produced when 2.5 g of calcium carbonate is decomposed completely according to the equation: CaCO3(s) → CaO(s) + CO2(g). The molar mass of CaCO3 is 100.09 g/mol.
A. 0.025 mol
B. 0.05 mol
C. 0.1 mol
D. 0.2 mol
Question 5
A 0.500 M solution of sodium hydroxide is mixed with a 0.250 M solution of hydrochloric acid. What is the pH of the resulting solution?
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 6
The reaction between H2 and O2 is catalyzed by Pt. The rate cons\tant (k) for this reaction is 2.5 × 10^\( -3 \) s^\( -1 \) at 298 K. If the initial concentrations of H2 and O2 are 0.100 M and 0.0500 M, respectively, what is the rate of reaction after 5.00 s?
A. 1.25 × 10^\( -5 \) M s^\( -1 \)
B. 2.50 × 10^\( -5 \) M s^\( -1 \)
C. 3.75 × 10^\( -5 \) M s^\( -1 \)
D. 5.00 × 10^\( -5 \) M s^\( -1 \)
Question 7
A 25.0 mL sample of a 0.100 M solution of NaOH is mixed with 25.0 mL of a 0.100 M solution of HCl. What is the pH of the resulting solution?
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 8
A 2.50-g sample of a metal oxide is treated with excess hydrochloric acid to produce 1.25 L of hydrogen gas at 25°C and 1 atm. What is the molar mass of the metal oxide?
A. 100 g/mol
B. 150 g/mol
C. 200 g/mol
D. 250 g/mol
Question 9
The solubility of sodium chloride (NaCl) in water is 36 g/100 mL at 25°C. Calculate the molar solubility of NaCl in water at 25°C.
A. 0.1 M
B. 0.2 M
C. 0.3 M
D. 0.4 M
Question 10
The rate cons\tant (k) of a first-order reaction is given by the equation: ln\( [A]t/[A]0 \) = -kt. If the half-life of the reaction is 10 minutes, calculate the rate cons\tant (k) if the initial concentration of the reac\tant is 0.5 M.
A. 0.069 min⁻¹
B. 0.069 hr⁻¹
C. 0.069 s⁻¹
D. 0.069 d⁻¹
Question 11
A solution of sodium hydroxide (NaOH) is added to a solution of hydrochloric acid (HCl) in a titration experiment. If 25 cm^3 of 0.1 M NaOH is required to neutralize 50 cm^3 of 0.2 M HCl, what is the concentration of the NaOH solution?
A. 0.05 M
B. 0.1 M
C. 0.2 M
D. 0.5 M
Question 12
A 1.0 M solution of Ca(OH)2 is mixed with a 1.0 M solution of HNO3. If the reaction is allowed to proceed to completion, what is the concentration of the remaining Ca(OH)2?
A. 0.5 M
B. 0.75 M
C. 1.0 M
D. 1.25 M
Question 13
A 0.100 M solution of HCl is titrated with 0.100 M NaOH. If the initial volume of HCl is 25.0 mL and the final volume is 50.0 mL, what is the pH of the resulting solution?
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 14
The reaction between sodium (Na) and chlorine (Cl2) produces sodium chloride (NaCl). Write the balanced chemical equation for this reaction.
A. 2Na + Cl2 → 2NaCl
B. Na + Cl2 → NaCl
C. 2NaCl + Cl2 → 2Na
D. Na + NaCl → Cl2
Question 15
A 100 mL sample of a solution containing 0.5 M NaCl is electrolyzed u\sing a current of 0.5 A for 10 minutes. Calculate the mass of Cl₂ gas produced at the anode.
A. 0.15 g
B. 0.30 g
C. 0.45 g
D. 0.60 g

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: