POST UTME ABU 2021 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
Determine the number of moles of $\text{CO}_2$ produced when 2.50 g of $\text{CaCO}_3$ is decomposed at cons\tant pressure and temperature.
A. 0.0500 mol
B. 0.100 mol
C. 0.150 mol
D. 0.200 mol
Question 2
A sample of a non-metallic element has a mass of 2.5 g and a volume of 2.0 cm^3. If the density of the element is 2.5 g/cm^3, what is its molar mass?
A. 10
B. 20
C. 30
D. 40
Question 3
A 2.50 g sample of nitrogen gas is collected over water at 25°C and 1.00 atm. Calculate the volume of the gas, in liters, assuming that the partial pressure of nitrogen is 0.950 atm.
A. 1.50 L
B. 2.00 L
C. 2.50 L
D. 3.00 L
Question 4
A diagram of a chromatography setup is shown below.
A. The column contains $\text{silica gel}$.
B. The beaker contains $\text{water}$.
C. The column contains $\text{water}$.
D. The beaker contains $\text{silica gel}$.
Question 5
The half-reaction for the oxidation of sulfur is: S(s) → S2O3^2-(aq). Calculate the s\tandard potential for this reaction.
A. -0.45 V
B. -0.50 V
C. -0.55 V
D. -0.60 V
Question 6
A 2.00 M solution of potassium hydroxide is mixed with a 1.00 M solution of hydrochloric acid. What is the concentration of the resulting solution?
A. 0.50 M
B. 1.00 M
C. 1.50 M
D. 2.00 M
Question 7
A solution contains 0.500 M $\text{Fe}^{2+}$ ions. What is the concentration of $\text{Fe}^{3+}$ ions if 0.0100 M $\text{KMnO}_4$ is added to the solution?
A. 0.00500 M
B. 0.0100 M
C. 0.0150 M
D. 0.0200 M
Question 8
Determine the s\tandard enthalpy of formation of CaO from the following data: ΔHf(Ca) = -1.85 kJ/mol, ΔHf(O) = -0.40 kJ/mol. The reaction is Ca + 1/2O2 → CaO.
A. -1.25 kJ/mol
B. -1.75 kJ/mol
C. -2.25 kJ/mol
D. -2.75 kJ/mol
Question 9
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, and ΔHf(C(s)) = 0 kJ/mol.
A. -1206.60 kJ/mol
B. -1206.61 kJ/mol
C. -1206.59 kJ/mol
D. -1206.62 kJ/mol
Question 10
A 0.1000 M solution of $\text{HCl}$ is mixed with a 0.1000 M solution of $\text{NaOH}$. What is the concentration of $\text{HCl}$ after the reaction is complete?
A. 0.0500 M
B. 0.0750 M
C. 0.100 M
D. 0.125 M
Question 11
A sample of oxygen gas is collected over water at 25°C and 1.00 atm. If the partial pressure of oxygen is 0.800 atm, what is the volume of the gas, in liters?
A. 1.00 L
B. 1.25 L
C. 1.50 L
D. 2.00 L
Question 12
A 2.00 M solution of H2SO4 is titrated with 1.00 M NaOH. Calculate the pH of the solution after 25.0 mL of NaOH has been added.
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 13
A 100 mL sample of a solution containing 0.500 M H2SO4 is titrated with 0.500 M NaOH. Calculate the pH of the solution at the equivalence point.
A. 7.00
B. 8.00
C. 9.00
D. 10.0
Question 14
A 25.0 mL sample of a solution containing 0.100 M NaCl is titrated with 0.100 M AgNO3. Calculate the volume of AgNO3 required to reach the equivalence point.
A. 12.5 mL
B. 25.0 mL
C. 37.5 mL
D. 50.0 mL
Question 15
A diagram of a titration setup is shown below.
A. The burette contains $\text{NaOH}$.
B. The beaker contains $\text{HCl}$.
C. The burette contains $\text{HCl}$.
D. The beaker contains $\text{NaOH}$.

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