POST UTME DELSU 2021 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A solution contains 0.1 M NaCl. What is the concentration of Cl- ions in the solution?
A. 0.05 M
B. 0.1 M
C. 0.15 M
D. 0.2 M
Question 2
A 1.00 M solution of a weak acid (HA) is titrated with a 1.00 M solution of a strong base (NaOH). The pH of the solution after the addition of 20.0 mL of NaOH is 4.00. Calculate the dissociation cons\tant (Ka) of the acid.
A. 1.0 x 10^\( -5 \)
B. 1.0 x 10^\( -4 \)
C. 1.0 x 10^\( -3 \)
D. 1.0 x 10^\( -2 \)
Question 3
A 25.0 mL sample of 0.500 M NaOH is titrated with 0.100 M HCl. What is the pH of the solution after the addition of 25.0 mL of HCl?
A. 1
B. 2
C. 3
D. 4
Question 4
A 2.00 M solution of HCl is prepared by dissolving 40.0 g of HCl in water to make 1000 mL of solution. Calculate the number of moles of HCl used in preparing the solution.
A. 0.200 mol
B. 0.400 mol
C. 0.800 mol
D. 1.60 mol
Question 5
A 1.00 L sample of a gas at 25.0°C and 1.00 atm is compressed to 2.00 atm at cons\tant temperature. What is the new volume of the gas?
A. 0.500 L
B. 1.00 L
C. 2.00 L
D. 4.00 L
Question 6
A 2.0 M solution of hydrochloric acid (HCl) is prepared by dissolving 40 g of HCl in 250 mL of water. What is the concentration of HCl in the solution?
A. 1.6 M
B. 2.0 M
C. 2.4 M
D. 2.8 M
Question 7
Determine the molar mass of a polymer with the following repeating unit: CH2-CH(CH3)-CH2-CH3. Assume that the polymer has a degree of polymerization of 100.
A. 500 g/mol
B. 600 g/mol
C. 700 g/mol
D. 800 g/mol
Question 8
A sample of a non-metallic element has a mass of 25.0 g and a volume of 10.0 mL. What is the density of the element in g/mL?
A. 2.50 g/mL
B. 2.00 g/mL
C. 1.50 g/mL
D. 1.00 g/mL
Question 9
A 2.00 g sample of a hydrocarbon is burned in a bomb calorimeter. The heat released is 12.0 kJ. What is the molar mass of the hydrocarbon?
A. 12.0 g/mol
B. 24.0 g/mol
C. 36.0 g/mol
D. 48.0 g/mol
Question 10
Determine the number of unpaired electrons in the ground state of a neutral atom of the element with atomic number 13.
A. 2
B. 4
C. 6
D. 8
Question 11
A 0.500 M solution of AgNO3 is prepared by dissolving 25.0 g of AgNO3 in water to make 1000 mL of solution. Calculate the number of moles of AgNO3 used in preparing the solution.
A. 0.125 mol
B. 0.250 mol
C. 0.500 mol
D. 1.00 mol
Question 12
A sample of a gas occupies a volume of 2.5 L at a pressure of 1.5 atm. If the temperature is increased to 300 K, what is the new volume of the gas?
A. 3.0 L
B. 3.5 L
C. 4.0 L
D. 4.5 L
Question 13
A metal M has an atomic radius of 135 pm. If the first ionization energy of M is 500 kJ/mol, what is the expected value of the second ionization energy?
A. 600 kJ/mol
B. 700 kJ/mol
C. 800 kJ/mol
D. 900 kJ/mol
Question 14
The reaction between zinc metal and copper(II) sulfate solution is represented by the equation: Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s). What is the oxidation state of copper in the product Cu(s)?
A. 0
B. +1
C. +2
D. -1
Question 15
A 2.5 L flask contains 0.25 mol of an ideal gas at 298 K. What is the pressure of the gas in the flask?
A. 1.01 × 10^5 Pa
B. 2.02 × 10^5 Pa
C. 3.03 × 10^5 Pa
D. 4.04 × 10^5 Pa

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