POST UTME NOUN 2020 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 10.0 mL sample of 0.100 M NaOH is titrated with 0.100 M HCl. Calculate the pH of the solution after the addition of 5.00 mL of HCl.
A. 2.00
B. 2.50
C. 3.00
D. 3.50
Question 2
A solution containing 0.1 M NaCl is electrolyzed u\sing a platinum electrode. If the electrolysis is carried out for 10 minutes, what is the volume of hydrogen gas produced at STP?
A. 0.5 L
B. 1 L
C. 2 L
D. 5 L
Question 3
A 0.1 M solution of CH3COOH is electrolyzed u\sing a platinum electrode. If the electrolysis is carried out for 10 minutes, what is the volume of hydrogen gas produced at STP?
A. 0.5 L
B. 1 L
C. 2 L
D. 5 L
Question 4
A solution contains 5.0 g of NaCl in 250 mL of water. What is the molarity of the solution?
A. 0.2 M
B. 0.5 M
C. 1.0 M
D. 2.0 M
Question 5
A reaction is represented by the equation: 2A + B → 2C + D. If the rate cons\tant (k) for the reaction is 0.05 s⁻¹, calculate the rate of reaction (r) if the concentration of A is 0.1 M and the concentration of B is 0.2 M.
A. 0.002 M/s
B. 0.0025 M/s
C. 0.003 M/s
D. 0.0035 M/s
Question 6
Determine the oxidation state of the underlined atom in the compound [Cr_2O_7^{2-}].
A. +6
B. +3
C. +2
D. +1
Question 7
A 0.1 M solution of HCl is mixed with a 0.1 M solution of NaOH. If the reaction is allowed to proceed to completion, what is the pH of the resulting solution?
A. 1
B. 2
C. 7
D. 14
Question 8
A 2.0 M solution of HCl is mixed with a 2.0 M solution of NaOH. If the initial concentrations of HCl and NaOH are 2.0 M each, what is the concentration of NaCl that will be formed after the reaction is complete?
A. 2.0 M
B. 1.0 M
C. 0.5 M
D. 0.25 M
Question 9
A 2.0 M solution of HCl is mixed with a 2.0 M solution of NaOH. If the initial concentrations of HCl and NaOH are 2.0 M each, what is the concentration of NaCl that will be formed after the reaction is complete?
A. 2.0 M
B. 1.0 M
C. 0.5 M
D. 0.25 M
Question 10
A 2.5 L flask contains 0.5 mol of an ideal gas at 27°C. Calculate the pressure of the gas in atm.
A. 1.0 atm
B. 2.0 atm
C. 3.0 atm
D. 4.0 atm
Question 11
A 2.0 M solution of H(NO)( is prepared by dissolving 40.0 g of HNO() in 1.0 L of water. What is the concentration of NO() ions in the solution?
A. 0.02 M
B. 0.04 M
C. 0.06 M
D. 0.08 M
Question 12
A sample of a gas is collected over water at a temperature of 25°C and a pressure of 1 atm. If the partial pressure of the gas is 0.5 atm, what is the mole \fraction of the gas in the gas mixture?
A. 0.25
B. 0.5
C. 0.75
D. 1.0
Question 13
The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. Calculate the s\tandard enthalpy of formation of C2H6(g) if the s\tandard enthalpy of formation of H2(g) is -285.8 kJ/mol.
A. -83.8
B. -85.8
C. -87.8
D. -89.8
Question 14
A solution of sodium hydroxide (NaOH) has a pH of 12. If the concentration of NaOH is 0.1 M, calculate the concentration of hydrogen ions (H⁺) in the solution.
A. 1.0 × 10⁻¹² M
B. 1.0 × 10⁻¹¹ M
C. 1.0 × 10⁻¹⁰ M
D. 1.0 × 10⁻⁹ M
Question 15
A 2.0 M solution of H(NO)( is prepared by dissolving 40.0 g of HNO() in 1.0 L of water. What is the concentration of OH() ions in the solution?
A. 0.02 M
B. 0.04 M
C. 0.06 M
D. 0.08 M

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