Burette

Definition

A burette is a graduated glass tube with a tap or stopcock at the bottom, used in volumetric analysis to deliver an accurately measured volume of a liquid, typically for titrations in acid-base chemistry.

5 Must Know Facts For Your Next Test

1. Burettes are commonly used in acid-base titrations to accurately measure the volume of a titrant (a solution of known concentration) added to reach the equivalence point.
2. The graduations on the burette allow for precise measurement of the volume of titrant added, typically in increments of 0.1 mL or smaller.
3. Proper burette technique involves ensuring the burette is filled correctly, reading the meniscus accurately, and carefully controlling the flow rate of the titrant.
4. Burettes are typically made of glass and have a stopcock at the bottom to control the flow of the titrant solution.
5. The initial and final volumes of the titrant in the burette are recorded to calculate the volume of titrant used, which is then used to determine the concentration or amount of the analyte in the sample.

Review Questions

• Explain the role of a burette in an acid-base titration and how it is used to determine the concentration of an unknown solution.
  • In an acid-base titration, a burette is used to accurately measure the volume of a titrant (a solution of known concentration) that is added to a sample of unknown concentration until the reaction reaches the equivalence point, as indicated by a color change or other endpoint. By recording the initial and final volumes of the titrant in the burette, the volume of titrant used can be calculated. This volume, along with the known concentration of the titrant, can then be used to determine the concentration or amount of the analyte in the original sample.
• Describe the key features of a burette and how they contribute to its use in volumetric analysis.
  • A burette is a graduated glass tube with a stopcock at the bottom. The graduations on the burette allow for precise measurement of the volume of liquid dispensed, typically in increments of 0.1 mL or smaller. The stopcock at the bottom of the burette enables the user to carefully control the flow rate of the titrant solution, which is crucial for accurately reaching the endpoint of the titration. The combination of the graduated scale and the stopcock allows the burette to deliver an accurately measured volume of a liquid, making it an essential tool for volumetric analysis techniques like acid-base titrations.
• Analyze the importance of proper burette technique in ensuring the accuracy and reliability of titration results.
  • Proper burette technique is essential for obtaining accurate and reliable results in acid-base titrations. Ensuring the burette is filled correctly, reading the meniscus accurately, and carefully controlling the flow rate of the titrant are all critical steps. Improper technique, such as parallax error when reading the meniscus or uneven flow of the titrant, can lead to significant errors in the measured volume and, consequently, the calculated concentration of the analyte. Mastering burette technique is a fundamental skill in volumetric analysis, as it directly impacts the quality and precision of the titration results.

Related terms

Titration: A laboratory technique used to determine the concentration of an unknown solution by gradually adding a known solution until the reaction is complete, as indicated by a color change or other endpoint.

Volumetric Analysis: A quantitative method of analysis that relies on measuring the volume of a solution to determine the concentration or amount of a substance.

Stopcock: A valve used to start, stop, or regulate the flow of a liquid or gas through a pipe or orifice.