POST UTME CRAWFORD UNIVERSITY 2022 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A diagram of a titration setup is shown below. What is the purpose of the burette?
A. To measure the volume of the solution
B. To measure the pH of the solution
C. To measure the concentration of the solution
D. To measure the temperature of the solution
Question 2
A solution of 0.1 M HCl is titrated with 0.1 M NaOH. What is the pH of the solution after 50 mL of NaOH has been added?
A. 1
B. 2
C. 3
D. 4
Question 3
A sample of a gas at 25°C and 1 atm is compressed to 2 atm. If the initial volume is 2 L, calculate the final volume of the gas.
A. 1 L
B. 2 L
C. 4 L
D. 8 L
Question 4
A 1.00-L flask contains 0.0500 M H2(g) and 0.0500 M I2(g) at 298 K. What is the equilibrium cons\tant for the reaction H2(g) + I2(g) ⇌ 2HI(g)?
A. 1.8 × 10^\( -3 \)
B. 1.8 × 10^\( -3 \)
C. 1.8 × 10^\( -3 \)
D. 1.8 × 10^\( -3 \)
Question 5
Determine the pH of a 0.1 M solution of HCl, given that the solubility product cons\tant (Ksp) of CaF2 is 3.9 x 10^-11.
A. 1
B. 2
C. 3
D. 4
Question 6
A 2.5 g sample of a metal carbonate is heated strongly. If 1.2 g of CO2 is produced, calculate the percentage purity of the carbonate.
A. 80%
B. 85%
C. 90%
D. 95%
Question 7
A 1 M solution of a weak base B is mixed with 1 M solution of a strong acid HCl. If the initial pH of the base solution is 10, calculate the pH of the resulting solution after the reaction is complete.
A. 4
B. 6
C. 8
D. 10
Question 8
A metal M reacts with oxygen to form a white solid. The reaction is as follows: 4M + 3O2 → 2M2O3. If 2.5 g of M2O3 is obtained from 2.5 g of M, calculate the percentage yield of M2O3.
A. 50%
B. 60%
C. 70%
D. 80%
Question 9
A metal M reacts with oxygen to form a basic oxide MO. If 2.5 g of M reacts with 1.5 g of O2, what is the mass of MO formed?
A. 3.5 g
B. 4.5 g
C. 5.5 g
D. 6.5 g
Question 10
A 0.1 M solution of a weak acid HA is mixed with a 0.1 M solution of a strong base NaOH. If the initial pH of the acid solution is 4.5, what is the pH of the resulting solution after the reaction is complete?
A. 4.5
B. 5.5
C. 6.5
D. 7.5
Question 11
A metal M (atomic number 23) has a density of 11.5 g/cm³. If a 2.5 g sample of the metal is obtained, what is the volume of the sample in cm³?
A. 0.22 cm³
B. 0.25 cm³
C. 0.28 cm³
D. 0.30 cm³
Question 12
A solution contains 0.1 M NaCl and 0.1 M CaCl₂. What is the concentration of Cl⁻ ions in the solution?
A. 0.1 M
B. 0.15 M
C. 0.2 M
D. 0.25 M
Question 13
A solution contains 0.1 M NaCl and 0.1 M CaCl2. If 10 mL of 1 M HCl is added to 90 mL of the solution, what is the concentration of Cl- ions in the resulting solution?
A. 0.1 M
B. 0.2 M
C. 0.3 M
D. 0.4 M
Question 14
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. What is the pKa of the acid?
A. 3.5
B. 4.5
C. 5.5
D. 6.5
Question 15
A solution contains 0.1 M HCl and 0.1 M NaOH. Calculate the pH of the solution after 50 mL of 0.1 M HCl is added to 50 mL of 0.1 M NaOH.
A. 1
B. 2
C. 3
D. 4

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