Beehive Shelves

Quick Answer: A beehive shelf is a small dome-shaped stand with a hole in the top and an opening in the side, placed in a pneumatic trough so a delivery tube can pass in through the side while an inverted gas jar or tube stands steadily over the hole to collect gas by displacement of water.

How the Beehive Shelf Works

Collecting gas over water is one of the first gas experiments in school chemistry. The awkward part is holding a water-filled jar upside down over the end of the delivery tube while the gas bubbles in. The shelf solves this: it sits on the floor of the trough under water, and the jar stands on its flat top. The delivery tube enters through the arched side opening and turns up to the hole beneath the jar, so the bubbles rise straight into it.

The name comes from the rounded dome, which resembles a traditional straw beehive. Beehive shelves have long been made of glazed earthenware or porcelain, which is heavy enough to stay put under water, and plastic versions are also made. The listing does not state the material or the size of the top hole, so check that the shelf suits your gas jars and delivery tube.

The shelf is used with a pneumatic trough and a gas jar with ground flange; once the jar is full, a glass plate is slid over its mouth under water before it is lifted out. Oxygen from hydrogen peroxide with a manganese(IV) oxide catalyst, and hydrogen from zinc and dilute acid, are the gases most often collected this way.

Experiments That Use the Shelf

• Collecting oxygen from hydrogen peroxide with manganese(IV) oxide.
• Collecting hydrogen from zinc and dilute sulfuric or hydrochloric acid.
• Measuring the gas given off in rate-of-reaction practicals by displacement into an inverted measuring cylinder.
• Collecting several jars of a gas in turn for glowing or burning splint tests.

Specifications

Care & Handling

• Discard the first jar of gas, which is mostly air pushed out of the apparatus.
• If the gas is made by heating, take the delivery tube out of the water before removing the flame, to prevent suck-back.
• Wash and dry the shelf after use and store it where it will not be chipped.
• Look for cracks before use; a cracked ceramic shelf can break when a jar is set down on it.

Why Choose LabEquip

School science departments and teacher-training colleges buy beehive shelves in class sets, one per trough. LabEquip lists them in General Lab Products; send the number of troughs and the gas jar size through the contact page.

Frequently Asked Questions

Why is it called a beehive shelf?

Its rounded dome shape resembles an old-fashioned straw beehive. The name has stuck in school chemistry for the small stand used in gas collection.

Which gases can be collected this way?

Gases that are only slightly soluble in water, such as oxygen, hydrogen and nitrogen, and carbon dioxide with some loss. Very soluble gases like ammonia and hydrogen chloride dissolve in the water instead of collecting.

How do I set up the shelf in the trough?

Fill the trough, sink the shelf so its top is a little below the surface, then fill a gas jar with water, cover it, invert it under water and stand it on the shelf over the hole. Pass the delivery tube in through the side opening.

Can a test tube be used instead of a gas jar?

Yes, for small volumes a boiling tube or test tube filled with water can stand over the hole, although narrow tubes are less steady than a gas jar and may need holding.

Why must the first jar of gas be thrown away?

At the start, the gas leaving the generator pushes out the air that filled the flask and tubing. The first jar is therefore mostly air and would give misleading test results.

How is suck-back avoided?

When heating a solid to make gas, lift the delivery tube out of the water before removing the flame. Otherwise, as the hot tube cools, water can be drawn back into it and crack the hot glass.

Last Updated: September 2026