Oxygen: Lab Preparation & Commercial Production, Properties and Uses | Chemistry for JAMB PDF Download

Introduction

• Oxygen is an indispensable element for sustaining life and finds extensive applications in various industries.
• This note will cover the laboratory preparation, commercial production from liquid air, properties, and uses of oxygen, with relevance to the JAMB Biology exam.

Laboratory Preparation of Oxygen

Decomposition of Potassium Chlorate

• One method for laboratory preparation involves the decomposition of potassium chlorate (KClO₃).
• Upon strong heating, potassium chlorate breaks down into potassium chloride (KCl) and oxygen gas (O₂).
• The balanced equation for this reaction is:
• 2KClO₃(s) → 2KCl(s) + 3O₂(g)
• Oxygen gas can be collected by displacing water in an inverted jar or by using a gas syringe.

Electrolysis of Water

• Another method for laboratory preparation is the electrolysis of water (H₂O).
• By passing an electric current through water, it can be split into oxygen gas (O₂) and hydrogen gas (H₂).
• The electrolysis process is represented by the following equation:
• 2H₂O(l) → 2H₂(g) + O₂(g)
• Oxygen gas is collected at the anode, while hydrogen gas is collected at the cathode.

Commercial Production of Oxygen from Liquid Air

• Liquid air is a mixture of nitrogen, oxygen, and other gases obtained by cooling and compressing atmospheric air.
• Commercial production of oxygen from liquid air involves a process known as fractional distillation.
• The air is first cooled and compressed to form a liquid state.
• This liquid air is then subjected to fractional distillation, which exploits the different boiling points of its components.
• Nitrogen, with a lower boiling point, evaporates first, leaving behind oxygen, which is collected and stored for various applications.

Properties of Oxygen

• Oxygen is a colorless, odorless, and tasteless gas.
• It is slightly soluble in water.
• Oxygen supports combustion and is necessary for respiration in organisms.
• It is paramagnetic, exhibiting weak attraction to a magnetic field.
• Oxygen is denser than air and slightly soluble in water.

Uses of Oxygen

Respiration

• Oxygen is vital for aerobic respiration, the process by which living organisms release energy from organic molecules.
• It serves as the final electron acceptor in the electron transport chain, facilitating the production of ATP.

Combustion and Oxidation

• Oxygen supports combustion and is required for various industrial processes.
• It is used in oxy-fuel welding and cutting, as well as in the production of steel and other metals.

Medical Applications

• Oxygen is used in medical settings to aid patients with respiratory difficulties.
• It is administered through oxygen masks or nasal cannulas to increase oxygen levels in the blood.

Water Treatment

• Oxygen plays a crucial role in wastewater treatment plants.
• It enhances the biological degradation of organic matter, facilitating the removal of pollutants and supporting the growth of aerobic microorganisms.

Conclusion

• Oxygen is a vital gas that can be prepared in the laboratory through the decomposition of potassium chlorate or electrolysis of water.
• Commercially, oxygen is produced from liquid air using fractional distillation techniques.
• Oxygen possesses unique properties and is essential for respiration, combustion, medical applications, and water treatment.
• Understanding the laboratory preparation, commercial production, properties, and uses of oxygen is important for the JAMB Biology exam and for comprehending its significance in various fields.