Kipps Gas Generating Apparatus, Borosilicate Glass

Quick Answer: A Kipps apparatus, or Kipp’s gas generator, is a three-bulb glass apparatus that produces a gas from a solid and a liquid acid and stops automatically when the outlet tap is closed. This version is made of borosilicate glass and is used for carbon dioxide, hydrogen and hydrogen sulfide in laboratories.

How the Three Bulbs Control the Reaction

The apparatus, named after the Dutch pharmacist Petrus Jacobus Kipp, stacks three glass globes. The top globe is a reservoir with a long tube running down to the bottom globe. The middle globe holds lumps of the solid reagent, such as marble chips, zinc granules or iron(II) sulfide, and carries the gas outlet with its stopcock. Acid poured into the top fills the bottom globe and rises into the middle one, where it meets the solid and gas is produced.

With the tap shut, fresh gas collects in the middle globe and its growing pressure drives the acid downward, through the lowest globe and back up the central tube into the reservoir, until acid and solid no longer touch. Opening the tap releases the gas, the acid returns and production restarts. This hydrostatic switch gives a steady supply for hours without pumps or electricity.

Borosilicate glass has better resistance to chemical attack and to mechanical and thermal stress than ordinary soda-lime glass, which suits an apparatus that stands charged with acid for long periods. The clear glass Kipps apparatus and the plastic Kipps apparatus work the same way. Capacity and stopcock type are not stated in the listing.

Applications

• Supplying hydrogen sulfide for group precipitation in classical qualitative inorganic analysis, inside a fume cupboard
• Generating carbon dioxide by the action of dilute hydrochloric acid on marble chips, for limewater tests and fire-extinguishing demonstrations
• Producing hydrogen from zinc and dilute acid for gas property tests
• Providing a standing gas supply for several bench groups during a practical session

Care & Handling

• Charge the solid through the middle globe’s opening before adding acid, using lumps large enough not to fall into the bottom globe.
• Use dilute acid only, pour it slowly into the top globe, and lubricate the stopcock and ground joints lightly.
• Generate hydrogen sulfide only in a fume cupboard, and close the tap fully when gas is not being drawn.
• To discharge, drain the acid from the lower outlet into a suitable container, then rinse all three globes and the solid chamber with water.

Specifications

Why Choose LabEquip

Colleges and senior schools that teach salt analysis with hydrogen sulfide, and laboratories wanting a durable gas supply, often specify a borosilicate Kipps apparatus. The apparatus is available from LabEquip’s chemistry lab equipment range, with capacity requests handled through the contact page.

Frequently Asked Questions

How does the generator stop producing gas?

Closing the outlet tap traps the gas in the middle globe. Its pressure forces the acid down and away from the solid into the lower globe and reservoir, so contact is broken and gas production pauses until the outlet is reopened.

Which gases can it generate?

Any gas made from a lumpy solid and a liquid without heating. The usual ones are carbon dioxide from marble and dilute hydrochloric acid, hydrogen from zinc and dilute acid, and hydrogen sulfide when dilute hydrochloric acid acts on iron(II) sulfide.

Why can’t powders be used?

Fine powder falls through the gap into the bottom globe, where it stays in contact with acid all the time and keeps reacting even when the tap is closed. Lumps or granules stay in the middle globe, where the automatic control works.

Can the apparatus be heated?

No. The design only works for reactions that proceed at room temperature. Gases that need heat, such as chlorine from manganese(IV) oxide and concentrated hydrochloric acid, are made in a flask with a dropping funnel instead.

Why does borosilicate matter if nothing is heated?

Borosilicate glass is more resistant to chemical attack and less prone to cracking from knocks and temperature changes, which is useful in a heavy apparatus that stays charged with acid for long periods.

How is hydrogen sulfide handled safely?

It is toxic and dulls the sense of smell, so generate it only in a working fume cupboard, draw off just what is needed, and close the tap between uses. Many laboratories now use thioacetamide solution as an alternative source.

Last Updated: September 2026