Acids are classified into two groups known as strong acids and weak acids. The main difference between strong and weak acids is that strong acids dissociate completely in aqueous solutions whereas weak acids partially dissociate in aqueous solutions. Strong acids are molecules that completely dissociate into their ions when it is in water. The strength of an acid is characterized by their acid dissociation constant values K a. Normally, strong acids have a very large K a value. The stronger the acid, more easily it loses protons.
These protons are easily released due to the high polarity of the bond between H atom and the rest of the molecule. This polarity is determined by the electronegativity of two atoms involved in this bond. The deprotonation removal of a proton of a strong acid depends on the polarity and the size of the anion which the proton is attached to. But if the acid molecule has more than one protons that can be released, it can be shown as below.
The below example shows the dissociation of a diprotic acid. Here, the strong acid is Hydrogen Chloride. An acid is said to be weak if it ionizes partially or incompletely, giving off only some of its hydrogen atoms into the solution.
Hence, it is less capable as compared to a strong acid in giving off protons. Weak acids have higher pKa than strong acids. Ethanoic acid is a good example of a weak acid. The molecules react quite easily to ameliorate the acid and the H 2 O.
Whatever is left is the simple acetic acid systematically called ethanoic acid molecules. A strong acid is an acid that ionizes completely in an aqueous solution. In other words, a strong acid is always on its toes and quite efficient in giving off protons. A weak acid is one that ionizes partially in a solution.
It gives off only few of its hydrogen atoms in to the solution. Hence it is less capable than a strong acid. Strong acids will always show strong conductivity. Strong acids usually pass more current as compared to the weak acids for the same voltage and concentration. Weak acids have a low conductivity. They are poor conductors and show a low value for current passing. In a strong acid, the pH is lower than, generally 3. The points of difference between Strong and Weak Acids have been summarized below: Comparison chart.
Difference Between Strong and Weak Acid. In physical properties acids are sour, corrosive and harmful. This process is also known as neutralisation. The neutralised product will be less acidic as compared to the reactant acid.
Unlike strong acid, weak acids do not dissociate completely in bases and thus they dissolve partially in the bases to make the neutralised product after the procedure of neutralisation.
Their capacity of gaining electrons and releasing protons is less. They are also conductors of electricity but their conductivity is extremely low. Their current passing process is slow when compared to strong acid. Weak acids take time to react, they are slow. Their PH value is high ranging between 5 to below 7. They are less capable than the strong acids. They can even burn nostrils when smells and tastes sour. Some of the weak acids are used in food and beverages like phosphoric acid used in soft drinks, baking powder, also acts as neutralizing agent,etc.
Thus it is clear that weak acids are too weak and are edible for normal human beings. They are not corrosive and thus do not harm any person like in case of strong acids.
Weak acids are even sometimes considered good for health as well when taken in limits. But can cause harm when the limit is exceeded or if someone is allergic to any specific acid, like lactic acid.
Both strong and weak acids are different types of acids.
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