Three Neck Round Bottom Flask

A three-neck round bottom flask (often abbreviated as 3-neck RBF) is a specialized piece of borosilicate glass laboratory glassware commonly used in organic chemistry and chemical synthesis.

Features

• With Interchangeable Joints.
• All the three necks are vertical. The two side necks are 180° apart.
• Uniform wall thickness distribution and round-bottom shape make them ideal for heating.
• The shape facilitates uniform heating.
• Accessories, thermometer, column, dropping funnels, boiling capillaries, etc. can be fitted depending upon the application.
• Generally used in distillation and extraction processes

Common Applications

The three necks make it perfect for complex experimental setups in organic synthesis, reflux, and distillation:

1. Center Neck (Usually Vertical): Often used for the main piece of equipment, such as:
   • A condenser (for reflux or distillation).
   • A mechanical stirrer or magnetic stirring shaft.
2. Side Necks (Often Angled): Used for introducing or monitoring reagents, temperature, or atmosphere:
   • A thermometer or thermocouple to monitor the reaction temperature.
   • A dropping funnel or addition funnel to add liquid reagents slowly.
   • An inert gas inlet (like nitrogen or argon) for reactions sensitive to air or moisture.
   • A vacuum connection for distillation under reduced pressure.

In short, it’s used when a reaction needs to be heated/stirred while simultaneously adding reagents and monitoring the temperature or pressure.