POST UTME RHEMA UNIVERSITY 2024 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 5.0 mL sample of a 0.1 M solution of NaOH is titrated with a 0.2 M solution of HCl. Calculate the pH of the resulting solution.
A. 2
B. 3
C. 4
D. 5
Question 2
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 3
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 4
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 5
A sample of nitrogen gas occupies a volume of 2.5 L at a pressure of 1.5 atm and a temperature of 298 K. What is the number of moles of nitrogen gas present?
A. 0.1
B. 0.2
C. 0.3
D. 0.4
Question 6
A 1.0 M solution of CaCl2 is mixed with a 1.0 M solution of Na2SO4 in a 1:1 ratio. What is the concentration of Ca2+ ions in the resulting solution?
A. 0.5 M
B. 1.0 M
C. 1.5 M
D. 2.0 M
Question 7
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 8
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 9
A 1.0 M solution of NaCl is mixed with a 1.0 M solution of NaOH in a 1:1 ratio. What is the concentration of Cl- ions in the resulting solution?
A. 0.5 M
B. 1.0 M
C. 1.5 M
D. 2.0 M
Question 10
A 2.5 g sample of a non-metallic oxide of nitrogen is decomposed by heating with graphite in a stream of hydrogen gas. The volume of hydrogen gas produced at 25°C and 1 atm is 2.5 L. Calculate the molar mass of the oxide.
A. 60 g/mol
B. 80 g/mol
C. 100 g/mol
D. 120 g/mol
Question 11
A solution of 0.1 M NaCl is mixed with 0.1 M NaOH in a 1:1 ratio. If the reaction is allowed to proceed to equilibrium, what is the concentration of Cl- ions in the resulting solution?
A. 0.05 M
B. 0.1 M
C. 0.15 M
D. 0.2 M
Question 12
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 13
A 2.0 g sample of a metal is heated in a stream of hydrogen gas, producing 1.2 g of water. If the metal is composed of only one type of metal, what is the molar mass of the metal?
A. 40 g/mol
B. 60 g/mol
C. 80 g/mol
D. 100 g/mol
Question 14
A 10 mL sample of a 0.5 M solution of HCl is mixed with a 10 mL sample of a 0.5 M solution of NaOH. Calculate the resulting pH.
A. 2
B. 3
C. 4
D. 5
Question 15
A 0.1 M solution of a weak acid, HA, is titrated with 0.1 M NaOH. If the initial pH of the solution is 4.5, what is the pH after the addition of 10 mL of 0.1 M NaOH?
A. 5.5
B. 6.5
C. 7.5
D. 8.5

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