Exam Body

Year

Subject

Paper Type

POST UTME DELSU 2019 Chemistry | Objective

Are you preparing for POST UTME DELSU exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2019 Chemistry (Objective) questions designed to simulate the real exam environment.

Practice these randomly selected questions to test your readiness.

Question 1

A 0.1 M solution of a weak acid HA is mixed with 0.1 M solution of a strong base NaOH. If the initial pH of the acid solution is 3.5, what is the pH of the resulting solution after the reaction is complete?

Correct A. 2.5

B. 3.5

C. 4.5

D. 5.5

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 2

A 2.5 g sample of a hydrocarbon is found to have a density of 0.8 g/mL. If the molar mass of the hydrocarbon is 42 g/mol, what is the empirical formula of the hydrocarbon?

Correct A. C2H6

B. C3H8

C. C4H10

D. C5H12

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 3

A 25 mL sample of a 0.1 M solution of NaOH is titrated with a 0.1 M solution of HCl. If the initial pH of the NaOH solution is 12.5, what is the pH of the resulting solution after the reaction is complete?

A. 1.5

B. 2.5

C. 3.5

Correct D. 4.5

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 4

A 10 mL sample of a 0.05 M solution of Fe2+ is mixed with 10 mL of a 0.05 M solution of MnO4-. If the initial concentration of Fe2+ is 0.05 M, what is the concentration of Fe3+ after the reaction is complete?

Correct A. 0.02 M

B. 0.03 M

C. 0.04 M

D. 0.05 M

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 5

A 5 mL sample of a 0.1 M solution of H2SO4 is mixed with 5 mL of a 0.1 M solution of NaOH. If the initial pH of the H2SO4 solution is 2.5, what is the pH of the resulting solution after the reaction is complete?

A. 1.5

B. 2.5

C. 3.5

Correct D. 4.5

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 6

Calculate the pH of a solution containing 0.1 M HCl and 0.1 M NaOH. The dissociation cons\tant of HCl is 10^-7.

A. 1

B. 2

Correct C. 3

D. 4

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 7

A 25 mL sample of a solution containing 0.5 M H2SO4 is titrated with 0.5 M NaOH. Calculate the volume of NaOH required to reach the equivalence point.

A. 10 mL

Correct B. 20 mL

C. 30 mL

D. 40 mL

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 8

A 10 L sample of a solution containing 0.2 M HCl is mixed with 5 L of a solution containing 0.1 M NaOH. Calculate the pH of the resulting solution.

A. 1

Correct B. 2

C. 3

D. 4

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 9

A 50 mL sample of a solution containing 0.5 M H2SO4 is titrated with 0.5 M NaOH. Calculate the pH of the resulting solution at the equivalence point.

Correct A. 1

B. 2

C. 3

D. 4

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 10

A 100 mL sample of a solution containing 0.1 M HCl is mixed with 50 mL of a solution containing 0.2 M NaOH. Calculate the pH of the resulting solution.

A. 1

B. 2

Correct C. 3

D. 4

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 11

The reaction between chlorine gas and sodium hydroxide solution is represented by the equation: Cl2 + 2NaOH → NaCl + NaClO + H2O. What is the oxidation state of chlorine in the product NaClO?

A. 0

B. +1

Correct C. +3

D. +5

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 12

A 25 mL sample of a solution containing 0.1 M NaCl is titrated with 0.1 M AgNO3. The reaction is represented by the equation: 2AgNO3 + NaCl → Ag2Cl + 2NaNO3. Calculate the number of moles of AgNO3 required to titrate the sample.

A. 0.0025

Correct B. 0.005

C. 0.0075

D. 0.01

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 13

A solution containing 0.1 M HCl is mixed with a solution containing 0.1 M NaOH. The reaction is represented by the equation: HCl + NaOH → NaCl + H2O. Calculate the pH of the resulting solution.

Correct A. 7

B. 8

C. 9

D. 10

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 14

A diagram of a titration setup is shown below. What is the purpose of the burette in this setup?

Correct A. To measure the volume of the titrant

B. To measure the volume of the analyte

C. To mix the titrant and analyte

D. To measure the pH of the solution

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 15

A diagram of a chromatography setup is shown below. What is the purpose of the stationary phase in this setup?

Correct A. To separate the components of a mixture

B. To identify the components of a mixture

C. To measure the concentration of a component

D. To measure the pH of a solution

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 16

A 0.1 M solution of a weak acid HA is mixed with a 0.1 M solution of a weak base B. If the resulting solution has a pH of 4.5, what is the value of the acid dissociation cons\tant Ka?

Correct A. \( 10^{-4} \)

B. \( 10^{-5} \)

C. \( 10^{-6} \)

D. \( 10^{-7} \)

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 17

A polymer has a degree of polymerization (n) of 1000. If the polymer has a molecular weight of 500,000 g/mol, what is the molar mass of the repeating unit?

A. 500 g/mol

Correct B. 1000 g/mol

C. 2000 g/mol

D. 5000 g/mol

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 18

A gas at 25°C and 1 atm is compressed to 2 atm. If the volume of the gas is reduced by a factor of 2, what is the new temperature of the gas?

A. 50°C

B. 75°C

Correct C. 100°C

D. 125°C

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 19

A solution of 0.1 M HCl is mixed with a solution of 0.1 M NaOH. If the resulting solution has a pH of 7, what is the value of the acid dissociation cons\tant Ka?

A. \( 10^{-7} \)

B. \( 10^{-8} \)

C. \( 10^{-9} \)

Correct D. \( 10^{-10} \)

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 20

A 0.1 M solution of a weak acid HA is mixed with a 0.1 M solution of a weak base B. If the resulting solution has a pH of 5.5, what is the value of the acid dissociation cons\tant Ka?

A. \( 10^{-5} \)

Correct B. \( 10^{-6} \)

C. \( 10^{-7} \)

D. \( 10^{-8} \)

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 21

Determine the pH of a 0.1 M solution of HCl at 25°C.

A. 1

B. 2

C. 3

Correct D. 4

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 22

A 25 mL sample of 0.5 M H2SO4 is titrated with 0.5 M NaOH. Calculate the number of moles of H2SO4.

Correct A. 0.125

B. 0.25

C. 0.5

D. 1

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 23

The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. Calculate the s\tandard enthalpy of combustion of 1 mole of C6H12O6(s).

A. -2800

B. -2900

Correct C. -3000

D. -3100

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 24

A 10 mL sample of 0.1 M FeSO4 is electrolyzed for 5 minutes. Calculate the mass of Fe deposited.

A. 0.1

B. 0.2

Correct C. 0.3

D. 0.4

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 25

A solution contains 0.1 M NaCl and 0.1 M KNO3. Calculate the boiling point elevation.

A. 0.1

Correct B. 0.2

C. 0.3

D. 0.4

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows

Help others prepare! Share this practice hub:

Chat with Support