Basic Science Information: What is protonated acid?
Why does the molecule need to behave as an acid or base characteristic? In a molecule or compound, we always try to classify them like acid, base, and neutral species. Acid is releasing protons into the aqueous environment. That is the reason, this category of compounds generally called acid. But, if there is no proton in the molecule or compound to release, then how that becomes acid. In nature, all the molecules or compound are not having itself proton to lose to the aqueous environment. Because the living thing made by organic molecules in major proportion. It would not lose its proton to the aqueous environment.
When you come to the mineral acid category such as HCl, H₂SO₄, etc. It loses its proton into the aqueous environment. For example, the HCl molecule loses its proton in the water environment and forms a positive hydrogen ion. But now, proton contains only one nucleus without electron. Hydrogen is the only molecule in the periodic table which contains only one proton in the nucleus. So that means, its form in the subatomic nature. This is not the correct statement. Then, what happens?
Hydrogen positive ion goes on bind with the water molecule in the environment. These ions are called hydronium ions. It is obvious that hydronium ions are positive in charge. It is a little bigger than the water molecule in size. But due to its ionic nature, hydronium ion moves faster in the aqueous environment as compared with the huge crowd of water molecules. This process is called the mobility of ions in the aqueous environment.
But the the same process under the externally applied voltage with the help of two electrodes, it is called conductivity of hydronium ions. Whether pure water conducts electricity? No. It won't conduct an electric current. But, it depends on up to what applied voltage, if you increase the external voltage, the water molecule undergoes dissociation. This dissociation gives oxygen and hydrogen gaseous molecules as an outcome from this electrolysis.
During this electrolysis process under the applied voltage, water molecules undergo turbulence before their dissociation. In this process, it conducts electric current. The conductivity of an aqueous solution does not only depend on the presence of ions. It also depends on the applied voltage between the electrodes. A similar effect, we can observe from sulphuric acid also.
Acid further classified into strong and weak. These above-discussed acids come under the strong category. Why does it come that? This acid releases its hydrogen ions at a faster rate to the aqueous environment. That is the main reason, these acids kept in that category. What is a weak acid? The acid which releases its proton slowly into the aqueous environment is called weak acid.
Are these inorganic molecules only consider as an acid? In chemistry, we deal with three categories such as Inorganic, Organic and Hybrid materials. There is an acid in organic molecules also. For example, acetic acid is an example of a weak acid. It releases its proton very slowly to the aqueous environment due to the association property of the molecule.
We have some strong acid in them also. Acetic acid contains both an alkyl part and an acid functional part in it. The alkyl part of CH3 is replaced with more electronegative atom such as fluorine. It gives CF3 as a fluorinated form. This entire group act as an electron-withdrawing characteristic. It tries to pull the electrons from other parts of the same molecule. These entire phenomena induce the faster release of proton ion into water. That's how it becomes strong acid.
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