Exam Body

Year

Subject

Paper Type

POST UTME UI 2021 Chemistry | Objective

Are you preparing for POST UTME UI exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2021 Chemistry (Objective) questions designed to simulate the real exam environment.

Practice these randomly selected questions to test your readiness.

Question 1

A 2.50 g sample of a metal oxide is heated in a crucible until it decomposes completely. The mass of the metal obtained is 1.25 g. Calculate the percentage of metal in the original sample.

A. 40%

Correct B. 50%

C. 60%

D. 70%

Correct Answer: B

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

Question 2

A solution of 0.100 M NaCl is mixed with a solution of 0.100 M AgNO3. Calculate the concentration of the resulting solution.

A. 0.100 M

B. 0.200 M

Correct C. 0.300 M

D. 0.400 M

Correct Answer: C

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

Question 3

A 2.00 L flask contains 1.00 mol of an ideal gas at 298 K. Calculate the work done by the gas when it expands to 4.00 L against an external pressure of 1.00 atm.

A. 10.0 J

B. 20.0 J

Correct C. 30.0 J

D. 40.0 J

Correct Answer: C

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

Question 4

A 0.500 L solution of 0.100 M HCl is mixed with a 0.500 L solution of 0.100 M NaOH. Calculate the pH of the resulting solution.

A. 1.00

Correct B. 2.00

C. 3.00

D. 4.00

Correct Answer: B

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

Question 5

A 2.00 g sample of a metal is heated in a crucible until it decomposes completely. The mass of the metal obtained is 1.25 g. Calculate the percentage of metal in the original sample.

A. 40%

Correct B. 50%

C. 60%

D. 70%

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 CaCO3(s) from the following reaction: CaO(s) + CO2(g) → CaCO3(s).

Correct A. -1792.5 kJ/mol

B. -1792.8 kJ/mol

C. -1792.2 kJ/mol

D. -1792.1 kJ/mol

Correct Answer: A

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

Question 7

A 0.500 M solution of NaOH is mixed with a 0.500 M solution of HCl. What is the pH of the resulting solution?

A. 1.00

Correct B. 2.00

C. 3.00

D. 4.00

Correct Answer: B

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

Question 8

A sample of a metal (M) reacts with oxygen to form a white solid. The reaction is as follows: 4M(s) + 3O2(g) → 2M2O3(s). If 2.50 g of M reacts with 3.00 g of O2, what is the mass of M2O3 formed?

A. 6.25 g

Correct B. 6.50 g

C. 6.75 g

D. 7.00 g

Correct Answer: B

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

Question 9

A 2.00 M solution of H2SO4 is mixed with a 2.00 M solution of NaOH. What is the pH of the resulting solution?

A. 1.00

Correct B. 2.00

C. 3.00

D. 4.00

Correct Answer: B

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

Question 10

A sample of a hydrocarbon (CnH2n) has a molecular weight of 42.0 g/mol. What is the value of n?

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 11

A reaction is said to be at equilibrium when the rates of forward and reverse reactions are equal. Which of the following is a characteristic of a reaction at equilibrium?

Correct A. The concentrations of reac\tants and products remain cons\tant.

B. The reaction rate is zero.

C. The reaction is spon\taneous.

D. The reaction is non-spon\taneous.

Correct Answer: A

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

Question 12

A gas at 300 K has a volume of 2.5 L. If the temperature is increased to 400 K, what is the new volume of the gas?

A. 3.2 L

Correct B. 4.0 L

C. 5.0 L

D. 6.4 L

Correct Answer: B

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

Question 13

A solution of 0.1 M HCl is titrated with 0.1 M NaOH. What is the pH of the solution after 25 mL of NaOH has been added?

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 14

A sample of gas has a volume of 1.5 L at 300 K. If the pressure is increased to 2 atm, what is the new volume of the gas?

A. 1.2 L

B. 1.5 L

Correct C. 1.8 L

D. 2.0 L

Correct Answer: C

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

Question 15

A reaction has a s\tandard enthalpy change of -200 kJ/mol. What is the s\tandard entropy change of the reaction?

A. -200 J/K/mol

B. -400 J/K/mol

C. -600 J/K/mol

Correct D. -800 J/K/mol

Correct Answer: D

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

Question 16

Determine the major product of the reaction between 2-methylpropane and chlorine gas, given that the reaction is carried out in the presence of light.

A. 1-chloro-2-methylpropane

Correct B. 2-chloro-2-methylpropane

C. 1,2-dichloro-2-methylpropane

D. 2,2-dichloro-2-methylpropane

Correct Answer: B

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

Question 17

A 2.5 L flask contains 0.25 mol of an ideal gas at 298 K. Calculate the pressure of the gas u\sing the ideal gas law.

A. 1.01 x 10^3 Pa

Correct B. 2.02 x 10^3 Pa

C. 3.03 x 10^3 Pa

D. 4.04 x 10^3 Pa

Correct Answer: B

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

Question 18

A solution contains 0.1 M NaCl and 0.2 M Na2SO4. Calculate the total concentration of chloride ions in the 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 19

A 50 mL sample of a solution containing 0.5 M HCl is titrated with 0.5 M NaOH. Calculate the volume of NaOH required to reach the equivalence point.

A. 25 mL

Correct B. 50 mL

C. 75 mL

D. 100 mL

Correct Answer: B

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

Question 20

A 1.0 L flask contains 0.1 mol of N2 and 0.2 mol of O2 at 298 K. Calculate the partial pressure of N2 u\sing the ideal gas law.

Correct A. 1.01 x 10^3 Pa

B. 2.02 x 10^3 Pa

C. 3.03 x 10^3 Pa

D. 4.04 x 10^3 Pa

Correct Answer: A

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

Question 21

The reaction of cyclohexane with bromine in the presence of light produces a mixture of 1,2-dibromocyclohexane and 1,4-dibromocyclohexane. Which of the following statements is true about the reaction?

A. The reaction is an example of a substitution reaction.

B. The reaction is an example of an elimination reaction.

Correct C. The reaction is an example of a radical substitution reaction.

D. The reaction is an example of an electrophilic addition reaction.

Correct Answer: C

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

Question 22

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

Correct A. 7

B. 10

C. 14

D. 0

Correct Answer: A

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

Question 23

The diagram below shows a titration setup. What is the purpose of the burette?

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 24

The reaction of methane with chlorine produces a mixture of chloromethane and dichloromethane. What is the major product of the reaction?

Correct A. CH3Cl

B. CH2Cl2

C. CHCl3

D. CCl4

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

A. A neutral solution.

B. A basic solution.

Correct C. An acidic solution.

D. A salt solution.

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