Exam Body

Year

Subject

Paper Type

POST UTME UNIPORT 2018 Chemistry | Objective

Are you preparing for POST UTME UNIPORT exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2018 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 has a pH of 4.5. What is the concentration of the hydroxide ions in the solution?

Correct A. 1.0 x 10^-5 M

B. 1.0 x 10^-6 M

C. 1.0 x 10^-7 M

D. 1.0 x 10^-8 M

Correct Answer: A

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

Question 2

A polymer has a molecular weight of 100,000 g/mol and a degree of polymerization of 500. What is the molar mass of the repeating unit?

A. 200 g/mol

Correct B. 400 g/mol

C. 600 g/mol

D. 800 g/mol

Correct Answer: B

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

Question 3

A solution of HCl is titrated with a solution of NaOH. The initial pH of the HCl solution is 2.0. What is the pH of the solution after the addition of 20 mL of 0.1 M NaOH?

A. 3.0

Correct B. 4.0

C. 5.0

D. 6.0

Correct Answer: B

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

Question 4

A reaction is represented by the equation: 2A + B → 2C + D. If the rate of disappearance of A is 0.05 M/s and the rate of appearance of C is 0.02 M/s, what is the rate of appearance of D?

A. 0.01 M/s

Correct B. 0.02 M/s

C. 0.03 M/s

D. 0.04 M/s

Correct Answer: B

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

Question 5

A sample of gas has a volume of 2.5 L at a pressure of 1.5 atm and a temperature of 300 K. What is the volume of the gas at a pressure of 3.0 atm and a temperature of 400 K?

A. 1.0 L

B. 2.0 L

Correct C. 3.0 L

D. 4.0 L

Correct Answer: C

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

Question 6

A 25.0 mL sample of 0.100 M HCl is titrated with 0.100 M NaOH. Calculate the pH of the solution after the addition of 25.0 mL of NaOH.

A. 2.00

Correct B. 3.00

C. 4.00

D. 5.00

Correct Answer: B

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

Question 7

A polymer has a molecular weight of 50,000 g/mol and a degree of polymerization of 500. Calculate the molar mass of the repeating unit.

A. 100 g/mol

B. 200 g/mol

Correct C. 50 g/mol

D. 25 g/mol

Correct Answer: C

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

Question 8

A 2.00 L sample of 0.100 M HCl is titrated with 0.100 M NaOH. Calculate the number of moles of NaOH required to reach the equivalence point.

Correct A. 0.0100 mol

B. 0.0200 mol

C. 0.0300 mol

D. 0.0400 mol

Correct Answer: A

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

Question 9

A 1.00 L sample of 0.100 M NaOH is titrated with 0.100 M HCl. Calculate the pH of the solution after the addition of 20.0 mL of HCl.

A. 2.00

B. 3.00

Correct C. 4.00

D. 5.00

Correct Answer: C

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

Question 10

A 3.00 L sample of 0.100 M HCl is titrated with 0.100 M NaOH. Calculate the number of moles of HCl present in the initial solution.

A. 0.0300 mol

B. 0.0400 mol

Correct C. 0.0500 mol

D. 0.0600 mol

Correct Answer: C

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

Question 11

The half-life of a radioactive subs\tance is 5 years. If the initial amount of the subs\tance is 100g, how much of the subs\tance will remain after 10 years?

A. 50g

B. 75g

Correct C. 87.5g

D. 100g

Correct Answer: C

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

Question 12

A solution of 0.1M HCl is mixed with a solution of 0.1M NaOH. What is the pH of the resulting solution?

A. 1

Correct B. 7

C. 9

D. 11

Correct Answer: B

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

Question 13

The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. What is the s\tandard enthalpy of formation of H2O(l)?

Correct A. -285.8 kJ/mol

B. -241.8 kJ/mol

C. -393.5 kJ/mol

D. -801.8 kJ/mol

Correct Answer: A

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

Question 14

A 2.0 M solution of HCl is mixed with a 2.0 M solution of NaOH. What is the concentration of the resulting solution?

Correct A. 1.0 M

B. 2.0 M

C. 3.0 M

D. 4.0 M

Correct Answer: A

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

Question 15

The half-life of a radioactive subs\tance is 5 years. If the initial amount of the subs\tance is 100g, how much of the subs\tance will remain after 10 years?

A. 50g

B. 75g

Correct C. 87.5g

D. 100g

Correct Answer: C

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

Question 16

The reaction between nitrogen dioxide and water is given by the equation: 3NO2 + H2O → 2HNO3 + NO. If 2.5 moles of NO2 react with excess water, calculate the number of moles of HNO3 produced.

Correct A. 1.67

B. 2.5

C. 3.33

D. 4.0

Correct Answer: A

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

Question 17

The s\tandard enthalpy of formation of CO2 is -393.5 kJ/mol. Calculate the s\tandard enthalpy of formation of H2O(g) if the s\tandard enthalpy of formation of H2(g) is 0 kJ/mol and the s\tandard enthalpy of formation of O2(g) is 0 kJ/mol.

Correct A. -393.5

B. -394.5

C. -395.5

D. -396.5

Correct Answer: A

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

Question 18

The pH of a solution is given by the equation: pH = -\log[H+]. If the concentration of H+ ions in a solution is 1.0 x 10^-3 M, calculate the pH of the solution.

A. 2

Correct B. 3

C. 4

D. 5

Correct Answer: B

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

Question 19

The reaction between sodium hydroxide and hydrochloric acid is given by the equation: NaOH + HCl → NaCl + H2O. If 2.0 moles of NaOH react with excess HCl, calculate the number of moles of NaCl produced.

A. 1.0

Correct B. 2.0

C. 3.0

D. 4.0

Correct Answer: B

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

Question 20

The s\tandard enthalpy of formation of CO is -110.5 kJ/mol. Calculate the s\tandard enthalpy of formation of H2(g) if the s\tandard enthalpy of formation of H2O(g) is -241.8 kJ/mol and the s\tandard enthalpy of formation of O2(g) is 0 kJ/mol.

Correct A. -31.3

B. -32.3

C. -33.3

D. -34.3

Correct Answer: A

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

Question 21

The pH of a solution is given by the equation: pH = -\log[H+]. If the concentration of H+ ions in a solution is 1.0 x 10^-4 M, calculate the pH of the solution.

A. 3

Correct B. 4

C. 5

D. 6

Correct Answer: B

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

Question 22

In the context of environmental chemistry, what is the primary mechanism by which pollu\tants are transported from the atmosphere to the soil?

Correct A. Dry deposition

B. Wet deposition

C. Runoff

D. Leaching

Correct Answer: A

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

Question 23

A solution of 0.1 M HCl is electrolyzed u\sing a platinum electrode. If the cell potential is 2.0 V, what is the mass of hydrogen gas produced at the cathode in 2 hours?

A. 1.2 g

B. 1.5 g

Correct C. 1.8 g

D. 2.0 g

Correct Answer: C

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

Question 24

The reaction of an alkane with chlorine gas in the presence of light produces a chloroalkane. If 1.0 g of the alkane is reacted with 1.0 g of chlorine gas, what is the percentage yield of the chloroalkane if 0.8 g of the product is obtained?

Correct A. 80%

B. 85%

C. 90%

D. 95%

Correct Answer: A

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

Question 25

A solution of 0.1 M HCl is electrolyzed u\sing a platinum electrode. If the cell potential is 2.0 V, what is the mass of hydrogen gas produced at the cathode in 2 hours?

A. 1.2 g

B. 1.5 g

Correct C. 1.8 g

D. 2.0 g

Correct Answer: C

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