Exam Body

Year

Subject

Paper Type

POST UTME OSUSTECH 2020 Chemistry | Objective

Are you preparing for POST UTME OSUSTECH 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 metal oxide, M2O3, is reduced to its corresponding metal, M, by heating it in a stream of hydrogen gas. The reaction is as follows: M2O3 + 3H2 → 2M + 3H2O. If 2.50 g of M2O3 is heated in a stream of hydrogen gas, and 1.50 g of water is collected, what is the percentage yield of the reaction?

A. 50%

B. 60%

Correct C. 70%

D. 80%

Correct Answer: C

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

Question 2

A 1.00 L sample of a gas at 25°C and 1.00 atm is collected over water at 25°C. If the vapor pressure of water at 25°C is 23.8 mmHg, what is the partial pressure of the gas?

A. 760 mmHg

B. 737 mmHg

Correct C. 760 - 23.8 mmHg

D. 760 mmHg

Correct Answer: C

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

Question 3

A 2.00 M solution of NaOH is mixed with a 1.00 M solution of HCl. If 50.0 mL of the NaOH solution is mixed with 50.0 mL of the HCl solution, 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 4

A diagram of a titration setup is shown below. If 25.0 mL of 0.100 M NaOH is required to reach the equivalence point, what is the concentration of the HCl solution?

A. 0.100 M

Correct B. 0.0500 M

C. 0.200 M

D. 0.0500 M

Correct Answer: B

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

Question 5

A 1.00 L sample of a gas at 25°C and 1.00 atm is collected over water at 25°C. If the vapor pressure of water at 25°C is 23.8 mmHg, what is the partial pressure of the gas?

A. 760 mmHg

B. 737 mmHg

Correct C. 760 - 23.8 mmHg

D. 760 mmHg

Correct Answer: C

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

Question 6

The polymerization of styrene to polystyrene is an example of a ______ reaction.

A. chain reaction

B. step-growth reaction

C. condensation reaction

Correct D. addition reaction

Correct Answer: D

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

Question 7

The reaction of benzene with bromine in the presence of light is an example of a ______ reaction.

A. substitution reaction

B. elimination reaction

Correct C. addition reaction

D. oxidation reaction

Correct Answer: C

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

Question 8

The pH of a solution is 7. If the concentration of hydrogen ions is doubled, what will be the new pH?

Correct A. 6

B. 7

C. 8

D. 9

Correct Answer: A

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

Question 9

The rate of a chemical reaction is affected by the ______ of the reac\tants.

Correct A. concentration

B. temperature

C. pressure

D. volume

Correct Answer: A

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

Question 10

The equilibrium cons\tant (K) for a reaction is a measure of the ______ of the reaction.

A. rate

B. yield

Correct C. equilibrium

D. concentration

Correct Answer: C

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

Question 11

The s\tandard Gibbs free energy change for the reaction 2Ag+ + 2e- → 2Ag(s) is -0.80 V. Calculate the equilibrium cons\tant (K) for this reaction at 298 K.

Correct A. 1.4 × 10^6

B. 1.4 × 10^5

C. 1.4 × 10^3

D. 1.4 × 10^2

Correct Answer: A

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

Question 12

A 2.5 M solution of H2SO4 is mixed with 1.5 M solution of NaOH. Calculate the pH of the resulting solution.

A. 1.2

B. 1.5

Correct C. 1.8

D. 2.1

Correct Answer: C

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

Question 13

A 1.0 M solution of FeCl3 is mixed with 2.0 M solution of NaOH. Calculate the concentration of Fe(OH)3 formed.

A. 0.5 M

Correct B. 1.0 M

C. 1.5 M

D. 2.0 M

Correct Answer: B

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 1.0 M solution of NaOH. Calculate the concentration of H2O formed.

A. 1.0 M

B. 1.5 M

Correct C. 2.0 M

D. 2.5 M

Correct Answer: C

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

Question 15

A 1.5 M solution of FeCl3 is mixed with 2.5 M solution of NaOH. Calculate the concentration of Fe(OH)3 formed.

A. 0.75 M

B. 1.0 M

Correct C. 1.25 M

D. 1.5 M

Correct Answer: C

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

Question 16

A mixture of 2.50 g of sodium chloride (NaCl) and 1.50 g of glu\cose (C6H12O6) is dissolved in 100 mL of water. Calculate the molality of the solution.

A. 0.10 m

Correct B. 0.20 m

C. 0.30 m

D. 0.40 m

Correct Answer: B

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

Question 17

A 2.00 M solution of hydrochloric acid (HCl) is prepared by dissolving 36.5 g of HCl in water to make 1.00 L of solution. Calculate the concentration of the solution in g/L.

Correct A. 36.5 g/L

B. 37.0 g/L

C. 37.5 g/L

D. 38.0 g/L

Correct Answer: A

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

Question 18

A 1.00 L flask contains 0.500 mol of an ideal gas at 25°C. Calculate the pressure of the gas in atm.

Correct A. 1.00 atm

B. 1.01 atm

C. 1.02 atm

D. 1.03 atm

Correct Answer: A

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

Question 19

A solution contains 10.0 g of urea (CO(NH2)2) dissolved in 100 mL of water. Calculate the molarity of the solution.

A. 0.10 M

Correct B. 0.20 M

C. 0.30 M

D. 0.40 M

Correct Answer: B

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

Question 20

A 2.00 L flask contains 0.500 mol of an ideal gas at 50°C. Calculate the pressure of the gas in atm.

A. 1.00 atm

Correct B. 1.01 atm

C. 1.02 atm

D. 1.03 atm

Correct Answer: B

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 a 0.1 M solution of a strong base. If 25 mL of the base is required to reach the equivalence point, what is the number of moles of acid initially present?

A. 0.0025 mol

Correct B. 0.005 mol

C. 0.0075 mol

D. 0.01 mol

Correct Answer: B

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

Question 22

A metal (M) reacts with chlorine gas to form a white solid. The reaction is as follows: \[ \text{M} + \text{Cl}_2 \rightarrow \text{MCl}_2 \]. If 2.5 g of MCl_2 is produced from 1.5 g of M, what is the molar mass of M?

A. 20 g/mol

B. 30 g/mol

Correct C. 40 g/mol

D. 50 g/mol

Correct Answer: C

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

Question 23

A solution containing 0.1 M HCl is mixed with a solution containing 0.1 M NaOH. If 25 mL of the HCl solution is added to 25 mL of the NaOH solution, what is the pH of the resulting solution?

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 24

A diagram of a titration setup is shown below. If the burette contains 0.1 M HCl and the flask contains 25 mL of 0.1 M NaOH, what is the volume of HCl 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 25

A metal (M) reacts with oxygen gas to form a white solid. The reaction is as follows: \[ \text{M} + \text{O}_2 \rightarrow \text{MO}_2 \]. If 2.5 g of MO_2 is produced from 1.5 g of M, what is the molar mass of M?

A. 20 g/mol

B. 30 g/mol

Correct C. 40 g/mol

D. 50 g/mol

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