POST UTME RHEMA UNIVERSITY 2024 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 0.1 M solution of a weak acid HA is titrated with 0.1 M NaOH. At the equivalence point, the pH of the solution is 7. Calculate the initial concentration of the acid HA.
A. 0.1 M
B. 0.01 M
C. 0.001 M
D. 0.0001 M
Question 2
A sample of a metal (X) has a density of 11.5 g/cm3 and a mass of 25.0 g. If the metal is heated in a crucible and the resulting gas is collected over water, what is the volume of the gas at 25°C and 1.00 atm?
A. 1.20 L
B. 1.50 L
C. 2.00 L
D. 2.50 L
Question 3
A 10.0 mL sample of a 0.1 M solution of HCl is mixed with 20.0 mL of a 0.2 M solution of NaOH. What is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 4
A solution containing 0.100 M NaCl is mixed with a solution containing 0.0500 M AgNO3. If the resulting solution is allowed to s\tand for several days, what is the concentration of the precipitate AgCl?
A. 0.0500 M
B. 0.100 M
C. 0.150 M
D. 0.200 M
Question 5
A 10.0 mL sample of a 0.1 M solution of NaOH is mixed with 20.0 mL of a 0.2 M solution of HCl. What is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 6
A 0.1 M solution of a weak base, B, is titrated with 0.1 M HCl. If the initial pH of the solution is 9.5, what is the pH after the addition of 10 mL of 0.1 M HCl?
A. 8.5
B. 9.5
C. 10.5
D. 11.5
Question 7
A 10.0 mL sample of a 0.1 M solution of NaOH is mixed with 20.0 mL of a 0.2 M solution of HCl. What is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 8
A 5.00 g sample of calcium carbonate (CaCO3) is heated to produce calcium oxide (CaO) and carbon dioxide (CO2). If the molar mass of CaCO3 is 100.09 g/mol and the molar mass of CaO is 56.08 g/mol, what is the mass of CaO produced?
A. 28.0 g
B. 32.0 g
C. 36.0 g
D. 40.0 g
Question 9
A metal M has a s\tandard electrode potential of +0.5 V. What is the potential of the metal M electrode when it is in contact with a solution containing 0.1 M M^2+ ions?
A. +0.4 V
B. +0.5 V
C. +0.6 V
D. +0.7 V
Question 10
A polymer has a molecular weight of 500,000 g/mol. If 1 g of the polymer is dissolved in 100 mL of water, what is the concentration of the solution in g/L?
A. 0.5 g/L
B. 5 g/L
C. 50 g/L
D. 500 g/L
Question 11
A sample of a metal (X) has a density of 11.5 g/cm3 and a mass of 25.0 g. If the metal is heated in a crucible and the resulting gas is collected over water, what is the volume of the gas at 25°C and 1.00 atm?
A. 1.20 L
B. 1.50 L
C. 2.00 L
D. 2.50 L
Question 12
A 10 mL sample of a 0.5 M solution of NaOH is titrated with a 0.1 M solution of HCl. Calculate the number of moles of HCl required to neutralize the NaOH.
A. 0.05 mol
B. 0.1 mol
C. 0.15 mol
D. 0.2 mol
Question 13
Determine the number of moles of oxygen gas (O2) produced at s\tandard temperature and pressure (STP) when 2.50 g of potassium chlorate (KClO3) is decomposed according to the equation: 2KClO3(s) → 2KCl(s) + 3O2(g).
A. 0.0500 mol
B. 0.100 mol
C. 0.150 mol
D. 0.200 mol
Question 14
A 10.0 g sample of iron (Fe) is oxidized to form iron(III) oxide (Fe2O3). If the molar mass of Fe is 55.85 g/mol and the molar mass of Fe2O3 is 159.69 g/mol, what is the mass of Fe2O3 produced?
A. 34.5 g
B. 40.0 g
C. 45.5 g
D. 50.0 g
Question 15
A 1.0 L solution of a 0.1 M HCl is titrated with a 0.1 M NaOH solution. What is the pH of the solution at the equivalence point?
A. 1
B. 2
C. 3
D. 4

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