The vacuum adaptor is used in a distillation set-up:

• it connects to the lower end of the condensor and serves to direct the distilled liquid into the receiving flask

A "bent adaptor" would serve the same purpose in a simple or fractional distillation. A bent adaptor does not have the connection to a vacuum source, which is on the right hand side in the above photo. The advantage of a vacuum adaptor over a bent adaptor is the ability to serve not only in simple or fractional distillations, but in a "vacuum distillation". If the lower joint is connected to a round bottom flask, the system is closed to the atmosphere and can be connected to a vacuum source to create a distillation set-up under reduced pressure. This is illustrated in the figure below:

Location: student lab drawer equipment.

Cost: $17.10

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