Is it strong or weak in nature? Its conjugate acid-base pairs, etc. Therefore, the aqueous solution of acetic acid contains fewer hydrogen ions which ultimately makes it a weak acid. Arrhenius theory b. Bronsted-Lowry theory. Note :- Bronsted-Lowry theory is not limited to an aqueous solution, this theory state that a substance is said to be Bronsted-Lowry acid when it donates the proton to other reacting species, the reacting species should be base or very less acidic in nature because according to this theory-.
A substance can function as an Bronsted-Lowry acid only in the presence of a base. The presence of water solution is a must for knowing the acidic nature of substance according to Arrhenius theory.
For knowing whether acetic acid is strong or weak, look out the basic difference between a strong acid and weak acid-. They have a low pH value and good electrical conductivity properties. They have a high pK a or pH value with moderate electrical conductivity property and weak electrolyte compare to strong acid. The strength of an acid depends on its ability to ionize completely or partially in a solution. So, all molecules of acetic acid not ionized completely cause fewer hydrogen ions in the aqueous solution and we know the more the hydrogen ion present in the solution, the higher will be the acidic strength of that solution.
Also, the double arrow in the reaction of acetic acid and water shows that both forward and backward reactions occur at equilibrium. The acid dissociation constant value for acetic acid is 1. Note :- In weak acid, the backward is more dominating than forwarding reaction, as the splitting ions easily react with each other to reform the acid molecule.
In acetic acid structure, a CH 3 group is present which is also called the electron-donating group, this CH 3 donates the electron or you can say it contributes the electron towards the O-H group, this increases the electron density on the oxygen atom attached to hydrogen.
Now oxygen has more electron density, so it is unable to pull the electrons from the hydrogen atom, hence the ionization of the O-H bond difficult. Or you can say the electron-donating group CH 3 decreases the polarity of the O-H bond, hence, the removal of hydrogen becomes more difficult in water solution.
Note: — More is the polarity, high is the acidic strength because polar bonds dissociate more easily in water solution, hence it is easier for the proton to leave the molecule. A base is a substance that accepts the proton from other compounds or releases OH — ion in an aqueous solution. When two atoms in a bond have nearly the same electronegativity values, the electrons are evenly shared and spend equal amounts of time associated with either atom a nonpolar bond.
On the other hand, when there is a significant electronegativity difference between the atoms, there is a separation of charge; as a result, electrons are drawn more to one atom than to the other polar bond or ionic bond. Hydrogen atoms have a slight positive charge when bonded to an electronegative element. If there is less electron density associated with hydrogen, it becomes easier to ionize and the molecule becomes more acidic. Weak acids form when there isn't enough polarity between the hydrogen atom and the other atom in the bond to allow for easy removal of the hydrogen ion.
Another factor that affects the strength of an acid is the size of the atom bonded to hydrogen. As the size of the atom increases, the strength of the bond between the two atoms decreases. This makes it easier to break the bond to release the hydrogen and increases the strength of the acid. Actively scan device characteristics for identification.
Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Related questions How do resonance structures affect acidity? How does carbon dioxide change the acid-base condition of a solution? Why do strong acids have a low pH? Is neutralization a double replacement reaction?
Why is NaH a strong base? Is HBr a strong acid? Weak acids ionize in a water solution only to a very moderate extent. The generalized dissociation reaction is given by:.
The strength of a weak acid is represented as either an equilibrium constant or a percent dissociation. The equilibrium concentrations of reactants and products are related by the acid dissociation constant expression, K a :. The K a of weak acids varies between 1. Acids with a K a less than 1. If acids are polyprotic, each proton will have a unique K a.
For example, H 2 CO 3 has two K a values because it has two acidic protons.
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