Difference Between SiO2 and CO2

The key difference between SiO2 and CO2 is that the SiO2 exists in solid phase whereas, the CO2 exists in gaseous phase at standard temperature and pressure conditions.

SiO2 is silicon dioxide. CO2 is carbon dioxide. Both silicon and carbon are group 14 elements in the periodic table of elements. These two oxides are the most common and stable oxides that they form. However, there are many differences between SiO2 and CO2. The key difference between SiO2 and CO2 is the phase at which they exist at standard temperature and pressure.

CONTENTS

1. Overview and Key Difference
2. What is SiO2
3. What is CO2
4. Side by Side Comparison – SiO2 vs CO2 in Tabular Form
5. Summary

What is SiO2?

SiO2 is silicon dioxide. It is the most common and stable oxide of silicon. This compound exists at the solid phase at standard temperature and pressure conditions. We can find it in nature as quartz. It exists as the major constituent of sand. The molar mass of this compound is 60.08 g/mol. It appears as a white solid. The melting and boiling points are 1,713 °C and 2,950 °C respectively.

Although silicon atom has only two oxygen atoms bonded to it, the geometry around the silicon atom is said to be tetrahedral. That is because this compound exists as a polymeric substance having SiO4 repeating units. There are many uses of this compound. It has applications for construction purposes, i.e. production of Portland cement. Also, it is the major ingredient in glass production. Further, SiO2 is useful in food and pharmaceutical applications as well, i.e. as a flow agent in powdered food.

What is CO2?

CO2 is carbon dioxide, and it is the most common and stable oxide of carbon. It exists in the gaseous phase at standard temperature and pressure conditions. CO2 naturally occurs as carbon dioxide gas in the atmosphere (about 0.03%). It is a colourless gas with a density that is higher than the dry air. The molar mass is 44.01 g/mol. At low concentrations it is odourless, but at high concentration, it has a sharp, acidic odour. The melting point of CO2 is −56.6 °C.

This molecule has a linear structure. The two oxygen atoms bind with the carbon atom via double bonds at opposite sides. The molecule has no electrical dipole because it is symmetric. Moreover, this compound is soluble in water; it forms the weak carbonic acid. Almost all aerobic organisms produce this gas in their respiration. It has many uses in the food industry, the oil industry, and the chemical industry. For instance, it is a precursor to many other chemicals such as methanol. Moreover, it is a food additive, and we use it for the production of carbonated soft drinks. Apart from that, we can use Carbon dioxide to extinguish flames.

What is the Difference Between SiO2 and CO2?

SiO2 is silicon dioxide, and CO2 is carbon dioxide. The key difference between SiO2 and CO2 is that the SiO2 exists in the solid phase whereas, the CO2 exists in the gaseous phase at standard temperature and pressure conditions. Moreover, Silicon dioxide has got a white colour while carbon dioxide is a colourless compound.

An important difference between SiO2 and CO2 is that the SiO2 has the tetrahedral geometry around silicon atom whereas the CO2 has the linear geometry around the carbon atom. A further difference between SiO2 and CO2 is that the SiO2 has single bonds between Si and O atoms while CO2 has double bonds between C and O atoms.

Summary – SiO2 vs CO2

Both Silicon (Si) and carbon (C) are group 14 elements in the periodic table. Moreover, the most common oxides of these elements are SiO2 and CO2. The key difference between SiO2 and CO2 is that the SiO2 exists in the solid phase whereas, the CO2 exists in the gaseous phase at standard temperature and pressure conditions.

Reference:

1. Britannica, The Editors of Encyclopaedia. “Carbon Dioxide.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 3 Jan. 2018. Available here   
2. “Silicon Dioxide.” Wikipedia, Wikimedia Foundation, 19 Nov. 2018. Available here  

Image Courtesy:

1.”Sample of silicon dioxide”By LHcheM – Own work, (CC BY-SA 3.0) via Commons Wikimedia  
2.”Soda bubbles macro”By Spiff (Public Domain) via Commons Wikimedia