The key difference between oxygen and carbon dioxide is that oxygen is a diatomic molecule having two oxygen atoms whereas carbon dioxide is a triatomic molecule having one carbon atom and two oxygen atoms.
Oxygen and carbon dioxide gases are two crucial constituents in the earth’s atmosphere. This is due to its importance for living organisms. Likewise, we need oxygen for respiration, and carbon dioxide emits during the process of respiration. We need this inhaled oxygen to produce energy (ATP) inside living cells from the process known as cellular respiration. On the other hand, plants utilize carbon dioxide for photosynthesis to produce carbohydrates. So, plants involve in maintaining the oxygen, carbon dioxide balance in the atmosphere.
CONTENTS
1. Overview and Key Difference
2. What is Oxygen
3. What is Carbon Dioxide
4. Side by Side Comparison – Oxygen vs Carbon Dioxide in Tabular Form
5. Summary
What is Oxygen?
Oxygen gas is a diatomic gas having two oxygen atoms bonded to each other via a double bond. These two oxygen atoms bind with each other via covalent chemical bonding. Hence, the oxygen molecule is a molecular compound (or a covalent compound). At standard temperature and pressure, this compound exists in the gaseous state.
Furthermore, our atmosphere contains about 21% of this gas. And, it is colourless and odourless. It is very important for life on earth because we use this gas for cellular respiration. Moreover, the oxygen atoms are essential components in biological systems included in bio-molecules such as carbohydrates, proteins and nucleic acids.
Figure 01: Diatomic Oxygen Molecule
Photosynthesis, on the other hand, is an important process in which plants use the energy of sunlight to produce carbohydrates and oxygen from water and carbon dioxide. An allotrope of oxygen, ozone, makes a layer at upper atmosphere which can protect us from harmful UV rays.
In brief, there are several favourable characteristics of this gas; it readily dissolves in water, which makes it easier to transport throughout the human body via body fluids. Moreover, we can obtain high purity oxygen gas from fractional distillation of liquefied air. This gas reacts with all the elements to form oxides except inert gases. Therefore, it is a good oxidizing agent. Oxygen is essential for combustion as well. Oxygen is useful in hospitals, welding, and in many other industries.
What is Carbon Dioxide?
Carbon dioxide is a triatomic molecule having one carbon atom and two oxygen atoms. Each oxygen atom forms a double bond with carbon. Hence the molecule has a linear geometry. The molecular weight of carbon dioxide is 44 g mole-1. The chemical formula is CO2, and it is a colourless gas. Furthermore, upon the dissolution in water, it forms carbonic acid. More importantly, this gas is denser than air. The concentration of carbon dioxide is 0.03% in the atmosphere.
Figure 02: Triatomic Molecule of Carbon Dioxide
However, the carbon dioxide amount in the atmosphere balances its content in the atmosphere through the carbon cycle. The sources of this gas that emits it to the atmosphere include some natural processes such as respiration, volcano eruption, and also through human activities like fossil fuel burning in vehicles and factories. Moreover, the process of photosynthesis removes carbon dioxide from the air, and thus, it deposits as carbonates in the long run.
The human interference (fossil fuel burning, deforestation) causes an imbalance in the carbon cycle, increasing the CO2 gas level. Global environmental problems like acid rain, greenhouse effect, global warming have resulted as a consequence of that. This gas is useful to make soft drinks, in the bakery industry, as a fire extinguisher, etc.
What is the Difference Between Oxygen and Carbon Dioxide?
Oxygen gas is a diatomic gas having two oxygen atoms bonded to each other via a double bond whereas carbon dioxide is a triatomic molecule having one carbon atom and two oxygen atoms. Hence, the key difference between oxygen and carbon dioxide is that oxygen is a diatomic molecule having two oxygen atoms whereas carbon dioxide is a triatomic molecule having one carbon atom and two oxygen atoms. Furthermore, the chemical formula of oxygen gas is O2 while the chemical formula of carbon dioxide gas is CO2.
Apart from that, another important difference between oxygen and carbon dioxide gases is that the oxygen content in air is comparatively very high (21%) than the content of carbon dioxide (0.03%). As another important difference between these two gases, we can take the role of each gas in the respiration process; we inhale oxygen gas while exhaling carbon dioxide gas.
Summary – Oxygen vs Carbon Dioxide
Oxygen and carbon dioxide are gaseous components in air of the atmosphere. The key difference between oxygen and carbon dioxide is that oxygen is a diatomic molecule having two oxygen atoms whereas carbon dioxide is a triatomic molecule having one carbon atom and two oxygen atoms.
Reference:
1. “Oxygen.” Wikipedia, Wikimedia Foundation, 26 Oct. 2018. Available here
2. “Carbon Dioxide.” Wikipedia, Wikimedia Foundation, 7 Nov. 2018. Available here
Image Courtesy:
1.”Oxygen molecule”By Ulflund – Own work, (CC0) via Commons Wikimedia
2.”Carbon-dioxide-3D-vdW”By Jacek FH – Own work (CC BY-SA 3.0) via Commons Wikimedia