Carbon Dioxide

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Carbon Dioxide Definition

Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms bonded together. It is one of the important ingredients in photosynthesis, the process by which green plants prepare food and energy. It is a colorless, odorless gas and is soluble in water, ethanol, and acetone, It has a melting point of -55.6°C and has a boiling point of -78.5°C, It has a density of 1.977g/ml. 

Carbon dioxide is an important greenhouse gas that helps to trap heat in our atmosphere, but it is a minor component of Earth’s atmosphere. Atmospheric CO2 can be extracted from natural sources like volcanic outgassing, combustion of organic matter, and the respiration processes of living aerobic organisms and man-made sources of carbon dioxide can be obtained from the burning of fossil fuels for power generation and transport use. It reacts with water to produce carbonic acid. It reacts with alkalis to give carbonates and bicarbonates as a product. It is also produced by fermentation and cellular respiration. In this topic we have discussed CO2 definition, Now we will study about properties and uses of carbon dioxide.

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Properties of Carbon Dioxide

  • It is a colorless and odorless gas.

  • It is a non-flammable gas.

  • It is slightly toxic.

  • It is denser than air.

  •  It has a melting point of -55.6°C and has a boiling point of -78.5°C.

  •  It has a density of 1.977g/ml.

  • It is soluble in water, solubility decreases as temperature increases.

  • It forms a weak carbonic acid when dissolved in water. It turns lime water milky.

  • Equation which shows CO2 behaves as an acid:

CO2 + H2O  → H2CO3 → H+(aq) +  HCO3-(aq)

               (The reaction is reversible in nature).

  • Reaction with alkali to give carbonates and bicarbonates.

CO2  +  NaOH → NaHCO3

NaHCO3​ +NaOH ⇒ Na2CO3 +H2O

Now, let us know about some uses of CO2 gas.

Carbon Dioxide Uses

  • Plants convert carbon dioxide to oxygen during a process called photosynthesis, using both carbon and oxygen to make carbohydrates.

  • Carbon dioxide is also used as a refrigerant.

  • It is used as a fire extinguisher.

  • It is used in promoting the growth of plants in greenhouses.

  • It is used in carbonated beverages, soft drinks, and beers to make them fizzy.

  • Large quantities of solid carbon dioxide ( in the form of dry ice) are used in large-scale refrigeration.

  • It is one of the parts of medical gases because it promotes exhalation.

  • The Carbon dioxide released by baking powder or yeast that makes cake batter rise is the best example of the Uses of carbon dioxide in everyday life.

Harmful Effects of Carbon Dioxide

Due to several human activities, the amount of CO2 released into the atmosphere has been rising extensively during the past few years. There has been an increase in carbon dioxide concentrations in the atmosphere of about 280 ppm in 1850 to 364 ppm in 1998, the main reason is due to human activities during and after the industrial revolution. Humans have been increasing the amount of carbon dioxide in the air by burning fossil fuels, producing cement, deforestation, and by carrying out land clearing and forest combustion. About 24% of the current atmospheric CO2 concentrations exist due to these human activities, considered that there is no change in natural amounts of carbon dioxide. 

Emissions released from the burning of fossil fuels combine with moisture in the air. The result is precipitation with high acid content. This increase in CO2 is harmful to humans, aquatic animals, and plants. Incomplete combustion or burning of carbon-containing fuels, such as coal, oil, charcoal, wood, kerosene leads to the formation of Carbon Monoxide.

Carbon Monoxide

Carbon monoxide is a highly poisonous gas. It is a colorless and odorless gas and its presence is detected immediately. If inhaled, carbon monoxide readily combines with the hemoglobin of our blood. Hemoglobin helps in carrying oxygen from the lungs to the tissues. Oxygen combines with hemoglobin to form oxy-hemoglobin. Similarly, CO combines with hemoglobin to form carboxyhemoglobin.

The affinity of CO for hemoglobin is much more (about 200 times) than that of oxygen. In the presence of carbon monoxide, the oxygen-carrying capacity of the hemoglobin is decreased. The deficiency of oxygen in the blood can cause headaches, dizziness, cardiac and respiratory problems, and even death. Because of this reason, it is dangerous to sleep in a closed room with a coke fire burning inside because the burning coke in an insufficient supply of oxygen produces a lot of carbon monoxide that can cause death.

Preventive Measures

  • Moving to renewable sources of energy like solar energy, wind energy,  etc will reduce the use of fossil fuels. This will reduce the release of carbon dioxide into the atmosphere.

  • Planting more trees on a large scale can help in decreasing the release of carbon dioxide in the atmosphere.

  • The government should come up with strict policies to maintain the overall air quality of the city.

FAQ (Frequently Asked Questions)

1. Who discovered carbon dioxide?

Scottish chemist and physician Joseph Black, first identified carbon dioxide in the year 1750. At room temperature, carbon dioxide is an odorless, colorless gas, which is faintly acidic and is non-flammable.

Preparation method:

1. It is prepared by the complete combustion of carbon and carbon-containing fuels in excess of air.

2. It can be prepared in the laboratory by the action of dilute HCl on calcium carbonate.

2. Impact of Carbon dioxide on Human health?

Carbon dioxide emissions impact human health by displacing oxygen in the atmosphere. Breathing becomes more difficult as the carbon dioxide level rises. Exposure to CO2 can create serious health effects like headaches, dizziness, restlessness, difficulty in breathing, sweating, tiredness, increased heart rate, elevated blood pressure, coma, asphyxia, and convulsions.

3. What is dry ice?

Dry ice is a solid form of Carbon dioxide and is made by compressing carbon dioxide.

Its uses are:

It is used to preserve food, ice creams without using mechanical cooling, by using a non - cyclic refrigerator. It is also used to produce white smoke.