POST UTME AAUA 2021 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
In a titration experiment, 25.0 mL of 0.100 M NaOH is added to 20.0 mL of 0.0500 M HCl. What is the concentration of the HCl solution if the equivalence point is reached at 35.0 mL of NaOH?
A. 0.0500 M
B. 0.0502 M
C. 0.0505 M
D. 0.0510 M
Question 2
A 0.500 L sample of a solution containing 0.0500 g of NaCl is titrated with 0.100 M AgNO3. What is the concentration of the NaCl solution if the equivalence point is reached at 25.0 mL of AgNO3?
A. 0.0100 M
B. 0.0102 M
C. 0.0105 M
D. 0.0110 M
Question 3
Determine the number of moles of oxygen gas (O2) produced at s\tandard temperature and pressure (STP) when 2.5 moles of carbon monoxide (CO) react with excess oxygen according to the equation: 2CO + O2 → 2CO2.
A. 1.25
B. 2.5
C. 5.0
D. 7.5
Question 4
A 0.500 M solution of NaOH is mixed with 0.500 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 5
The reaction of sulfur dioxide with oxygen to form sulfur trioxide is an example of a redox reaction. Write the balanced chemical equation for this reaction, including the oxidation states of sulfur.
A. \( 2SO_2 + O_2 \rightarrow 2SO_3 \)
B. \( 2SO_2 + O_2 \rightarrow 2SO_4 \)
C. \( 2SO_2 + O_2 \rightarrow 2SO_3 \)
D. \( 2SO_2 + O_2 \rightarrow 2SO_2O_3 \)
Question 6
A 25.0 mL sample of 0.100 M NaOH is titrated with 0.0500 M HCl. Calculate the volume of HCl required to reach the equivalence point.
A. 50.0
B. 75.0
C. 100
D. 125
Question 7
The s\tandard Gibbs free energy change (ΔG°) for the reaction: 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s) is -1340.6 kJ/mol. Calculate the equilibrium cons\tant (K) for the reaction.
A. 10^\( -1340.6 \)
B. 10^\( -1340.7 \)
C. 10^\( -1340.8 \)
D. 10^\( -1340.9 \)
Question 8
A mixture of 2.50 g of sodium chloride (NaCl) and 1.50 g of calcium chloride (CaCl2) is dissolved in 100.0 mL of water. Calculate the molar concentration of the resulting solution.
A. 0.050 M
B. 0.075 M
C. 0.100 M
D. 0.125 M
Question 9
A 25.0 mL sample of 0.100 M NaOH is titrated with 0.0500 M HCl. Calculate the number of moles of HCl required to reach the equivalence point.
A. 0.00250
B. 0.00500
C. 0.00750
D. 0.0100
Question 10
The s\tandard enthalpy of formation of CO2 is -393.5 kJ/mol. Calculate the s\tandard enthalpy of combustion of 1 mol of methane.
A. \( -890.3 , \text{kJ/mol} \)
B. \( -890.8 , \text{kJ/mol} \)
C. \( -891.3 , \text{kJ/mol} \)
D. \( -891.8 , \text{kJ/mol} \)
Question 11
A solution contains 0.1 M H2SO4 and 0.1 M NaOH. Calculate the pH of the solution.
A. 1
B. 2
C. 3
D. 4
Question 12
A sample of a gas has a volume of 2.00 L at a pressure of 1.00 atm and a temperature of 25°C. What is the volume of the gas at a pressure of 2.00 atm and a temperature of 50°C?
A. 1.00 L
B. 2.00 L
C. 3.00 L
D. 4.00 L
Question 13
A gas at 25°C and 1 atm is compressed to 2 atm. What is the new volume of the gas?
A. 0.50 L
B. 1.00 L
C. 2.00 L
D. 4.00 L
Question 14
A 0.500 L sample of a solution containing 0.0500 g of NaCl is titrated with 0.100 M AgNO3. What is the concentration of the NaCl solution if the equivalence point is reached at 25.0 mL of AgNO3?
A. 0.0100 M
B. 0.0102 M
C. 0.0105 M
D. 0.0110 M
Question 15
A 0.5 M solution of NaOH is mixed with a 0.5 M solution of HCl. Calculate the pH of the resulting solution.
A. ( 7.00 )
B. ( 7.50 )
C. ( 8.00 )
D. ( 8.50 )

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: