key term - Titrant

Definition

A titrant is a solution of known concentration used in titrations to determine the concentration of an unknown solution. In acid-base titrations, the titrant typically contains a strong acid or base that reacts with the analyte, allowing for precise measurements to be made. The process involves the gradual addition of the titrant to the analyte until the reaction reaches its equivalence point, indicated by a color change from an indicator.

5 Must Know Facts For Your Next Test

1. Titrants are chosen based on their ability to react completely with the analyte in a predictable manner.
2. The concentration of the titrant must be accurately known for the calculations of the analyte's concentration to be valid.
3. Common titrants in acid-base reactions include sodium hydroxide (NaOH) for bases and hydrochloric acid (HCl) for acids.
4. In practice, a burette is often used to deliver the titrant dropwise into the analyte solution, allowing for careful monitoring.
5. The choice of indicator is crucial, as it should change color at or near the equivalence point of the titration.

Review Questions

• How does the choice of titrant influence the outcome of an acid-base titration?
  • The choice of titrant is critical because it directly affects the accuracy and reliability of the results obtained from an acid-base titration. A suitable titrant must react completely with the analyte and ideally should have a clear endpoint that can be detected with an appropriate indicator. If an unsuitable titrant is chosen, it may lead to incomplete reactions or ambiguous endpoints, thus skewing the calculated concentration of the analyte.
• What role does an indicator play in determining when to stop adding a titrant during a titration?
  • An indicator is essential in titrations because it provides a visual signal that indicates when the endpoint has been reached. As the titrant is added, the pH of the solution changes, and once it reaches a specific value, determined by the choice of indicator, the indicator changes color. This color change signifies that enough titrant has been added to react completely with the analyte, allowing for accurate measurement of its concentration.
• Evaluate how inaccuracies in measuring a titrant's concentration can affect experimental results in a titration.
  • Inaccuracies in measuring a titrant's concentration can have significant implications on experimental results during a titration. If the concentration is overestimated, it may lead to an underestimation of the analyte's concentration, and vice versa. These errors compound through calculations, potentially resulting in misleading conclusions about chemical properties or reactions. Thus, ensuring that the titrant's concentration is precise is crucial for obtaining valid and reproducible results.

Related terms

analyte:

The substance whose concentration is being determined in a titration.

equivalence point: The point in a titration where the amount of titrant added is exactly enough to completely react with the analyte.

indicator:

A chemical that changes color at a certain pH level, used to signal the endpoint of a titration.