Exam Body

Year

Subject

Paper Type

POST UTME NILE UNIVERSITY 2020 Chemistry | Objective

Are you preparing for POST UTME NILE UNIVERSITY exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2020 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 NaOH. If the resulting solution has a pH of 4.5, what is the value of the dissociation cons\tant of the acid (Ka)?

Correct A. 1.0 x 10^-5

B. 1.0 x 10^-4

C. 1.0 x 10^-3

D. 1.0 x 10^-2

Correct Answer: A

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

Question 2

A diagram of a titration setup is shown below. If 25.0 mL of 0.1 M NaOH is required to reach the equivalence point, what is the concentration of the acid (HA)?

A. 0.01 M

Correct B. 0.1 M

C. 1.0 M

D. 10.0 M

Correct Answer: B

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

Question 3

A 2.0 g sample of a compound is found to have a mass of 2.5 g when placed in a 10.0 mL solution of 0.1 M NaOH. What is the molar mass of the compound?

A. 50.0 g/mol

B. 100.0 g/mol

Correct C. 150.0 g/mol

D. 200.0 g/mol

Correct Answer: C

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

Question 4

A diagram of a chemical apparatus is shown below. If the apparatus is used to measure the pH of a solution, what is the pH of the solution?

A. 1.0

B. 2.0

Correct C. 3.0

D. 4.0

Correct Answer: C

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

Question 5

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

Correct A. 1.0 x 10^-5

B. 1.0 x 10^-4

C. 1.0 x 10^-3

D. 1.0 x 10^-2

Correct Answer: A

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

Question 6

A reaction is carried out in a bomb calorimeter at cons\tant volume. The reaction is exothermic and releases 12.5 kJ of heat energy. If the initial temperature of the reaction mixture is 298 K, what is the change in internal energy (ΔU) for the reaction?

A. 12.5 kJ

Correct B. -12.5 kJ

C. 0 kJ

D. 25 kJ

Correct Answer: B

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

Question 7

A 2.50 g sample of a metal is heated to 100°C and then dropped into 25.0 mL of water at 20.0°C. If the final temperature of the water is 22.5°C, what is the specific heat capacity of the metal?

A. 0.500 J/g°C

Correct B. 1.00 J/g°C

C. 2.00 J/g°C

D. 4.00 J/g°C

Correct Answer: B

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

Question 8

A solution of 0.100 M NaCl is prepared by dissolving 6.00 g of NaCl in 1.00 L of water. What is the concentration of Cl- ions in the solution?

Correct A. 0.100 M

B. 0.200 M

C. 0.300 M

D. 0.400 M

Correct Answer: A

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

Question 9

A 10.0 g sample of a metal is heated to 100°C and then dropped into 50.0 mL of water at 20.0°C. If the final temperature of the water is 22.5°C, what is the specific heat capacity of the metal?

A. 0.500 J/g°C

Correct B. 1.00 J/g°C

C. 2.00 J/g°C

D. 4.00 J/g°C

Correct Answer: B

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

Question 10

A solution of 0.0500 M HCl is prepared by dissolving 2.00 g of HCl in 1.00 L of water. What is the concentration of H+ ions in the solution?

Correct A. 0.0500 M

B. 0.100 M

C. 0.200 M

D. 0.400 M

Correct Answer: A

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

Question 11

A sample of a metal oxide is heated in a crucible. The resulting gas is collected over water and found to have a volume of 2.5 L at 20°C and 1.5 atm. If the gas is CO2, calculate the number of moles of CO2 produced.

A. 0.1 mol

Correct B. 0.2 mol

C. 0.3 mol

D. 0.4 mol

Correct Answer: B

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

Question 12

A solution of HCl is titrated with a solution of NaOH. The initial pH of the HCl solution is 2.5. After the addition of 25 mL of NaOH solution, the pH of the solution is 3.5. Calculate the concentration of the HCl solution.

A. 0.1 M

B. 0.2 M

Correct C. 0.3 M

D. 0.4 M

Correct Answer: C

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

Question 13

A redox reaction occurs between Fe2+ and Cr2+ ions. The reaction is as follows: Fe2+ + Cr2+ → Fe3+ + Cr3+. If 2.5 g of Fe2+ ions are added to 1.0 L of a solution containing 0.1 M Cr2+ ions, what is the concentration of Fe3+ ions produced?

A. 0.05 M

Correct B. 0.1 M

C. 0.15 M

D. 0.2 M

Correct Answer: B

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

Question 14

A catalyst is added to a reaction mixture containing 1.0 M H2 and 1.0 M O2. The reaction is as follows: 2H2 + O2 → 2H2O. If the reaction is allowed to proceed for 10 minutes, what is the concentration of H2 remaining?

A. 0.5 M

B. 0.6 M

Correct C. 0.7 M

D. 0.8 M

Correct Answer: C

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

Question 15

A solution of NH3 is prepared by dissolving 10 g of NH3 in 1.0 L of water. The pH of the solution is 9.5. Calculate the concentration of NH4+ ions present.

A. 0.1 M

B. 0.2 M

Correct C. 0.3 M

D. 0.4 M

Correct Answer: C

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

Question 16

A sample of an ideal gas is heated from 300 K to 400 K at cons\tant volume. What is the ratio of the final pressure to the initial pressure?

Correct A. 1.33

B. 1.5

C. 2

D. 3

Correct Answer: A

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

Question 17

A solution contains 10 g of glu\cose (C6H12O6) per 100 g of water. What is the molality of the solution?

A. 0.5 m

Correct B. 1 m

C. 2 m

D. 5 m

Correct Answer: B

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

Question 18

A colloidal solution contains 10 g of starch in 100 g of water. What is the volume of the solution that will have a concentration of 0.1 g/mL?

A. 100 mL

B. 200 mL

Correct C. 500 mL

D. 1000 mL

Correct Answer: C

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

Question 19

A sample of a gas has a volume of 2 L at a pressure of 1 atm and a temperature of 300 K. What is the volume of the gas at a pressure of 2 atm and a temperature of 400 K?

A. 4 L

B. 6 L

Correct C. 8 L

D. 10 L

Correct Answer: C

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

Question 20

A solution contains 10 g of sodium chloride (NaCl) per 100 g of water. What is the molarity of the solution?

A. 0.1 M

B. 0.5 M

Correct C. 1 M

D. 2 M

Correct Answer: C

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

Question 21

A 0.1 M solution of a monoprotic acid is titrated with 0.1 M NaOH. At the equivalence point, the pH of the solution is 7. Calculate the initial concentration of the acid.

A. 1 x 10^-3 M

Correct B. 1 x 10^-4 M

C. 1 x 10^-5 M

D. 1 x 10^-6 M

Correct Answer: B

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

Question 22

A 2.0 g sample of a subs\tance is dissolved in 100 mL of water. The resulting solution has a concentration of 0.02 M. Calculate the molar mass of the subs\tance.

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 23

A 1.0 M solution of a weak acid is titrated with 1.0 M NaOH. At the equivalence point, the pH of the solution is 7. Calculate the initial concentration of the acid.

A. 1 x 10^-1 M

Correct B. 1 x 10^-2 M

C. 1 x 10^-3 M

D. 1 x 10^-4 M

Correct Answer: B

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

Question 24

A 1.0 M solution of a weak base is titrated with 1.0 M HCl. At the equivalence point, the pH of the solution is 7. Calculate the initial concentration of the base.

A. 1 x 10^-1 M

Correct B. 1 x 10^-2 M

C. 1 x 10^-3 M

D. 1 x 10^-4 M

Correct Answer: B

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

Question 25

A 1.0 M solution of a weak acid is titrated with 1.0 M NaOH. At the equivalence point, the pH of the solution is 7. Calculate the initial concentration of the acid.

A. 1 x 10^-1 M

Correct B. 1 x 10^-2 M

C. 1 x 10^-3 M

D. 1 x 10^-4 M

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