Sources of gas

Cylinder

For commercially available gases, it may be possible to obtain these in a cylinder. There is a wide variety of cylinder designs, but for gas line work where only small quantities are required, lecture bottles (pictured below) are usually used. In this picture, the cylinder is connected to a needle valve in addition to the cylinder regulator. These two taps allow small quantities of gas to be released onto the gas line.

Reaction flask

There is a huge variety of different flasks used to produce gases. Probably the most well known is the Kipp's Apparatus. Many pieces of glassware are custom designed to suit the purpose of the reaction being undertaken to produce the gas, for example the flask below which is designed to be able to keep two liquids separate on a gas line, before the flask is then rotated in the joint (right) where it is connected to the gas line (often via a delivery tube), which allows the solution from one part of the flask to run into the other half and mix.

Delivery tube

A delivery tube is often used to connect a reaction flask to the gas line. The tube is pre-filled with a material to 'scrub' the gas before it reaches the line. This might be to remove water vapour or other materials in the reaction (eg volatile liquids) and prevent these reaching the gas line.