Definition and nature of buffer solutions
Definition of Buffer Solutions, Buffer, Principle, Function, Nature, Type, Kind & Example: Is a solution containing a mixture of weak acids and their conjugate bases, or vice versa
Definition of Buffer Solution
Buffer solution (buffer) is a solution that can maintain (maintain) its pH from the addition of acids, bases, or dilution by water. The pH of the buffer solution does not change (constant) after the addition of acids, bases, or water. The buffer solution can neutralize the addition of acids and bases from the outside.
Buffer solution or also called buffer solution or buffer solution is a solution that can maintain the pH value even if added a little acid, a little base, or a little water (dilution). This is because the buffer solution contains a "buffer" solute consisting of acidic and basic components. The acid component serves to withstand the increase in pH, while the alkaline component functions to withstand the decrease in pH.
A buffer solution or a buffer solution is a solution consisting of:
Mix of weak acid with salt.
Example: A mixture of CH3COOH (weak acid) solution and CH3COONa (conjugate base) solution forms an acid buffer solution, with the reaction:
CH3COOH + NaOH → CH3COONa + H2O.
Mix weak base with salt.
Example: A mixture of NH4OH solution (weak base) and NH4CL solution (conjugated acid) to form a buffer base solution, with the reaction:
NH4OH + HCl → NH4CL + H2O.
Kind of Buffer Solution
Components of the Buffer Solution are divided into:
Acidic buffer / buffer solution
This solution maintains the pH in the acidic region (pH <7). To get this solution can be made from weak acids and salts which are the conjugate base of the acid. The other way is to mix a weak acid with a strong base where the weak acid is mixed in excess. The mixture will produce a salt containing a conjugate base from the corresponding weak acid. In general, strong bases used such as sodiumNa), potassium, barium, calcium, and others.
The way it works can be seen in a buffer solution containing CH3COOH and CH3COO - which experiences equilibrium. With the following process:
On Acid Addition
Adding acid (H +) will shift the equilibrium to the left. Where the added H + ion reacts with the CH3COO ion - it forms the CH3COOH molecule.
CH3COO– (aq) + H + (aq) → CH3COOH (aq)
On base addition
If what is added is a base, the OH - ion from the base will react with the H + ion to form water. This will cause the equilibrium to shift right so that the H + ion concentration can be maintained. Thus, the addition of a base causes a decrease in the acid component (CH3COOH), not the H + ion. The added base reacts with CH3COOH acid to form CH3COO ions - and water.
CH3COOH (aq) + OH– (aq) → CH3COO– (aq) + H2O (l)
Alkaline buffers
This solution maintains the pH in an alkaline region (pH> 7). To get this solution can be made from weak bases and salts, whose salts come from strong acids. The other way is by mixing a weak base with a strong acid where the weak base is mixed in excess.
The way it works can be seen in a buffer solution containing NH3 and NH4 + that is experiencing equilibrium. With the following process:
On Acid Addition
If an acid is added, the H + ion from the acid will bind the OH– ion. This causes the equilibrium to shift to the right, so that the concentration of OH- ions can be maintained. Besides this addition causes a decrease in the base component (NH3), instead of the OH- ion. The acid added reacts with the base NH3 to form NH4 + ions.