Exam Body

Year

Subject

Paper Type

POST UTME WELLSPRING UNIVERSITY 2025 Chemistry | Objective

Are you preparing for POST UTME WELLSPRING UNIVERSITY exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2025 Chemistry (Objective) questions designed to simulate the real exam environment.

Practice these randomly selected questions to test your readiness.

Question 1

The atomic radius of an element is 100 pm. If the element is in the third period of the periodic table, what is the value of its atomic radius in the next period?

Correct A. 120 pm

B. 110 pm

C. 130 pm

D. 140 pm

Correct Answer: A

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

Question 2

A solution of NaCl is prepared by dissolving 35.5 g of NaCl in 250 mL of water. What is the molarity of the solution?

A. 0.1 M

Correct B. 0.2 M

C. 0.3 M

D. 0.4 M

Correct Answer: B

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

Question 3

A sample of CO2 gas is collected over water at a temperature of 25°C and a pressure of 1 atm. What is the partial pressure of CO2 in the gas mixture?

Correct A. 0.9 atm

B. 0.8 atm

C. 0.7 atm

D. 0.6 atm

Correct Answer: A

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

Question 4

A 2.5 M solution of HCl is prepared by dissolving 25 g of HCl in 1 L of water. What is the pH of the solution?

A. 1.3

Correct B. 1.4

C. 1.5

D. 1.6

Correct Answer: B

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

Question 5

A 1.0 M solution of NaOH is prepared by dissolving 40 g of NaOH in 1 L of water. What is the pOH of the solution?

A. 1.4

Correct B. 1.5

C. 1.6

D. 1.7

Correct Answer: B

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

Question 6

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

A. -110.5 kJ/mol

B. -110.5 kJ/mol

C. -110.5 kJ/mol

Correct D. -110.5 kJ/mol

Correct Answer: D

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

Question 7

A sample of a metal (M) has a density of 11.5 g/cm^3. If the volume of the sample is 2.5 cm^3, calculate the mass of the sample.

A. 28.75 g

B. 28.75 g

C. 28.75 g

Correct D. 28.75 g

Correct Answer: D

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

Question 8

The s\tandard enthalpy of formation of NH3(g) is -45.9 kJ/mol. Calculate the s\tandard enthalpy of formation of N2(g) if the s\tandard enthalpy of formation of H2(g) is 0 kJ/mol.

A. 0 kJ/mol

B. 0 kJ/mol

C. 0 kJ/mol

Correct D. 0 kJ/mol

Correct Answer: D

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

Question 9

A sample of a non-metal (X) has a density of 2.5 g/cm^3. If the volume of the sample is 5.0 cm^3, calculate the mass of the sample.

A. 12.5 g

B. 12.5 g

C. 12.5 g

Correct D. 12.5 g

Correct Answer: D

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

Question 10

The s\tandard enthalpy of formation of H2O(l) is -285.8 kJ/mol. Calculate the s\tandard enthalpy of formation of H2(g) if the s\tandard enthalpy of formation of O2(g) is 0 kJ/mol.

A. 0 kJ/mol

B. 0 kJ/mol

C. 0 kJ/mol

Correct D. 0 kJ/mol

Correct Answer: D

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

Question 11

The reaction of potassium permanganate with hydrogen peroxide in acidic medium is a classic example of a redox reaction. Write the balanced chemical equation for this reaction.

Correct A. 2KMnO4 + 3H2O2 + H2SO4 → K2SO4 + 2MnSO4 + 4H2O + 3O2

B. 2KMnO4 + 3H2O2 + H2SO4 → K2SO4 + 2MnSO4 + 4H2O

C. 2KMnO4 + 3H2O2 → K2SO4 + 2MnSO4 + 4H2O

D. 2KMnO4 + 3H2O2 → K2SO4 + 2MnSO4 + 4H2O + 3O2

Correct Answer: A

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

Question 12

The atomic radius of an element is the dis\tance from the nucleus to the outermost electron in a neutral atom. Which of the following tr\ends is observed for atomic radius across a period in the periodic table?

A. Increases across a period

Correct B. Decreases across a period

C. Remains cons\tant across a period

D. Increases and then decreases across a period

Correct Answer: B

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

Question 13

The reaction of an alkane with chlorine gas in the presence of light is an example of a substitution reaction. Write the general equation for this reaction.

Correct A. R-H + Cl2 → R-Cl + HCl

B. R-H + Cl2 → R-Cl + HCl + Cl

C. R-H + Cl2 → R-Cl + HCl + Cl2

D. R-H + Cl2 → R-Cl + HCl + R-H

Correct Answer: A

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

Question 14

The half-life of a radioactive subs\tance is the time required for half of the initial amount of the subs\tance to decay. Which of the following statements is true about the half-life of a radioactive subs\tance?

Correct A. The half-life of a radioactive subs\tance is cons\tant and indep\endent of the initial amount of the subs\tance

B. The half-life of a radioactive subs\tance is dep\endent on the initial amount of the subs\tance

C. The half-life of a radioactive subs\tance is cons\tant and dep\endent on the initial amount of the subs\tance

D. The half-life of a radioactive subs\tance is indep\endent of the initial amount of the subs\tance

Correct Answer: A

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

Question 15

The reaction of an acid with a base is an example of a neutralization reaction. Write the general equation for this reaction.

Correct A. HCl + NaOH → NaCl + H2O

B. HCl + NaOH → NaCl + H2O + Na

C. HCl + NaOH → NaCl + H2O + O2

D. HCl + NaOH → NaCl + H2O + Cl2

Correct Answer: A

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

Question 16

The reaction of an alkene with bromine water is an example of an addition reaction. Write the general equation for this reaction.

Correct A. C2H4 + Br2 → C2H4Br2

B. C2H4 + Br2 → C2H4Br + HBr

C. C2H4 + Br2 → C2H4Br + Br

D. C2H4 + Br2 → C2H4Br + H2

Correct Answer: A

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

Question 17

The reaction of an acid with a carbonate is an example of a decomposition reaction. Write the general equation for this reaction.

Correct A. HCl + Na2CO3 → NaCl + H2O + CO2

B. HCl + Na2CO3 → NaCl + H2O + Na2O

C. HCl + Na2CO3 → NaCl + H2O + CO

D. HCl + Na2CO3 → NaCl + H2O + O2

Correct Answer: A

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

Question 18

The reaction of an alkene with ozone is an example of an addition reaction. Write the general equation for this reaction.

Correct A. C2H4 + O3 → C2H4O3

B. C2H4 + O3 → C2H4O + O2

C. C2H4 + O3 → C2H4O + O

D. C2H4 + O3 → C2H4O + H2O

Correct Answer: A

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

Question 19

A 0.1 M solution of CuSO4 is prepared by dissolving 3.3 g of CuSO4 in 100 mL of water. What is the molar concentration of Cu2+ ions in the solution?

A. 0.1 M

B. 0.05 M

Correct C. 0.01 M

D. 0.005 M

Correct Answer: C

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

Question 20

A sample of a polymer is found to have a molecular weight of 50,000 g/mol. If 2.5 g of the polymer is dissolved in 100 mL of solvent, what is the concentration of the solution in g/L?

A. 0.05 g/L

Correct B. 0.5 g/L

C. 5 g/L

D. 50 g/L

Correct Answer: B

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

Question 21

A solution of NaOH is prepared by dissolving 10 g of NaOH in 100 mL of water. What is the concentration of the solution in M?

A. 0.1 M

Correct B. 0.5 M

C. 1 M

D. 2 M

Correct Answer: B

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

Question 22

A sample of a metal is found to have a density of 8.5 g/cm3. If the volume of the sample is 2.5 cm3, what is the mass of the sample in g?

Correct A. 21.25 g

B. 22.5 g

C. 23.75 g

D. 25 g

Correct Answer: A

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

Question 23

A solution of HCl is prepared by dissolving 10 g of HCl in 100 mL of water. What is the concentration of the solution in M?

A. 0.1 M

Correct B. 0.5 M

C. 1 M

D. 2 M

Correct Answer: B

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

Question 24

The reaction of cyclohexane with bromine in the presence of light produces a mixture of products. What is the major product of this reaction?

A. 1,2-dibromocyclohexane

B. cis-1,2-dibromocyclohexane

C. trans-1,2-dibromocyclohexane

Correct D. cyclohexene

Correct Answer: D

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

Question 25

The diagram below shows the structure of a polymer. What type of polymer is it?

Correct A. Polyethylene

B. Polypropylene

C. Polyvinyl chloride

D. Polystyrene

Correct Answer: A

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