Titration Curves

• Titration curves provide a graphical representation of the change in pH throughout the titration process.
• In a strong acid-strong base titration, the curve will have a sharp vertical section at the equivalence point, which signifies the complete neutralisation of the acid. The pH at this point will be 7.
• Conversely, in a weak acid-strong base titration, the curve will have a more gradual slope and the pH at the equivalence point will be greater than 7, indicating that the solution is slightly basic.
• A buffer region can be identified in the titration curve of a weak acid-strong base or a weak base-strong acid. This is a region of the curve where the pH remains largely constant, despite the addition of more acid or base. This shows the buffering capacity of the weak acid or base.
• The half-equivalence point is a crucial part of titration curves of weak acids or bases. This is the point where exactly half of the acid or base has been neutralised. At this point, the concentration of the acid or base is equal to that of its conjugate, and the pH of the solution is equal to the pKa of the acid or the pKb of the base.
• A titration curve can be used to determine the pKa or pKb of an unknown weak acid or base. It’s done by identifying the half-equivalence point and taking the pH at that point as the pKa or pKb.
• The end point of titration is determined by the sharp change in colour of an indicator. The choice of indicator should be based on its pH change range and the pH at the equivalence point of the titration.
• Understanding titration curves and being able to extract and analyse information from them is vital for solving problems related to acid-base equilibria, buffers, and pH calculations. Identifying the different points and regions of the curve and knowing what they represent can greatly assist with this.