Pure water in contact with air has a higher conductivity than the same water that has had nitrogen gas bubbled through it. Why?
Some CO2 from the air dissolves in the water to form carbonic acid. That dissociates to form a few ions.
CO2 + H2O ==> H2CO3 ==> H^+ + HCO3^-
Ah, conductivity, the electrically charged topic! Well, it's a funny thing, you see. When air meets pure water, it brings along some tiny impurities with it, like dust and dissolved ions. These impurities allow the water to carry electrical charges more easily, like having a bunch of tiny conductors floating around.
But when nitrogen gas joins the party, it prefers to keep to itself, not mingling with the water's ions. So, it leaves the water feeling a bit more shy when it comes to conducting electricity. It's like a room full of introverts – not much electrical excitement going on!
In simpler terms, it's the impurities in the air that make all the difference here. They give the water a conductivity boost, while nitrogen gas just appears NitROGENius at making the water a bit more resistant to conducting electricity.
The conductivity of water is mainly influenced by the presence of ions, which are electrically charged particles. In pure water, a small amount of the water molecules naturally dissociate into ions: positively charged hydrogen ions (H+) and negatively charged hydroxide ions (OH-). This dissociation process, known as self-ionization, forms a small concentration of these ions.
When water comes into contact with air, it can dissolve certain gases, including carbon dioxide (CO2). The dissolved CO2 reacts with water to form carbonic acid (H2CO3). Carbonic acid further dissociates into hydrogen ions and bicarbonate ions (HCO3-). This increases the overall concentration of ions in the water, thus enhancing its conductivity.
On the other hand, when nitrogen gas (N2) is bubbled through water, it does not react with water or significantly increase the concentration of ions. Nitrogen gas is relatively unreactive and does not contribute to the conductivity of water.
Therefore, pure water in contact with air has a higher conductivity compared to water that has had nitrogen gas bubbled through it due to the presence of additional ions formed from the reaction between water and dissolved gases like carbon dioxide.
The difference in conductivity between pure water in contact with air and water that has had nitrogen gas bubbled through it can be attributed to the presence of dissolved ions in the water.
Pure water (H2O) is a weak conductor of electricity because it consists mainly of water molecules, which are electrically neutral. However, water has the ability to dissolve small amounts of ionic compounds, such as salts, acids, and bases. When these compounds dissolve in water, they break down into their constituent ions, which are charged particles. These ions can freely move in the solution, which allows the water to conduct electricity.
In the case of pure water in contact with air, there is a possibility that the water can dissolve some atmospheric gases, such as carbon dioxide (CO2), which can react with water to form carbonic acid (H2CO3). This reaction releases hydrogen ions (H+), increasing the concentration of ions in the water and making it a better conductor of electricity.
On the other hand, when nitrogen gas (N2) is bubbled through water, it does not react with water as readily as carbon dioxide. Therefore, the water remains relatively free of dissolved ions, resulting in lower conductivity compared to the pure water in contact with air.
So, the key factor affecting the conductivity difference is the presence of dissolved ions in the water, which can come from atmospheric gases or other solutes added to the water.