O2

Definition

Oxygen, or O2, is a colorless, odorless, and highly reactive gas that is essential for the survival of most living organisms on Earth. It is the second most abundant element in the Earth's atmosphere and plays a crucial role in various chemical and biological processes.

5 Must Know Facts For Your Next Test

1. Oxygen is a diatomic gas, meaning its molecules consist of two oxygen atoms bonded together.
2. Oxygen is essential for cellular respiration, the process by which living organisms convert food into energy in the form of ATP.
3. The molar mass of oxygen (O2) is 32.00 g/mol, which is used in calculating the formula mass of chemical compounds containing oxygen.
4. Oxygen is a highly reactive element and can form various compounds, such as water (H2O), carbon dioxide (CO2), and metal oxides.
5. Oxygen is produced naturally through the process of photosynthesis, where plants and other photosynthetic organisms use sunlight, carbon dioxide, and water to produce oxygen as a byproduct.

Review Questions

• Explain the role of O2 in the phases and classification of matter.
  • Oxygen (O2) is a gas at room temperature and standard atmospheric pressure, and it is classified as a diatomic molecule. As a gas, oxygen can undergo phase changes, such as liquefaction and solidification, under different temperature and pressure conditions. The phase and classification of oxygen are important in understanding its behavior and interactions with other substances in chemical reactions and physical processes.
• Describe how the molar mass of O2 is used in the formula mass and mole concept.
  • The molar mass of oxygen (O2), which is 32.00 g/mol, is an essential factor in calculating the formula mass of chemical compounds containing oxygen. The formula mass, also known as the molecular weight, is the sum of the atomic masses of the elements in a compound's formula. Understanding the molar mass of O2 is crucial in applying the mole concept, which relates the number of particles (atoms, molecules, or ions) to the mass of a substance, allowing for the quantitative analysis of chemical reactions and the determination of the number of moles of a substance.
• Analyze the importance of O2 in the writing and balancing of chemical equations.
  • Oxygen (O2) is a key reactant in many chemical equations, particularly in combustion reactions and reactions involving oxidation-reduction processes. The presence of O2 in the reactants or products of a chemical equation must be properly accounted for when balancing the equation to ensure the conservation of mass and charge. Additionally, the molar mass of O2 is used to determine the stoichiometric relationships between the reactants and products, which is essential for understanding and predicting the quantities of substances involved in a chemical reaction.

Related terms

Oxidation: The process of adding oxygen to a substance or removing hydrogen from it, resulting in an increase in the oxidation state of an element.

Combustion: A chemical reaction that occurs between a fuel and oxygen, releasing heat and light energy.

Respiration: The process by which organisms convert organic compounds, such as glucose, into carbon dioxide and water, releasing energy in the form of ATP.