Quick Answer:The Flat Bottom Flask, also known as a Florence flask, is a borosilicate glass 3.3 flask with a spherical body and a flat base, so it stands on the bench or a heating plate without a support ring. It is used to heat, boil and store liquids.
Last updated: 18 October 2026
Key Features
Spherical body spreads heat evenly when the contents are heated or boiled.
Flat base lets the flask stand on its own.
Narrow or wide neck, with a plain rim for stoppers or an interchangeable ground-glass joint.
High resistance to thermal shock and localised heating.
Inert to most acids, alkalis and organic solvents.
Technical Specifications
Specification
Value
Material
Borosilicate glass 3.3
Shape
Spherical body, flat base
Capacities
50, 100, 250, 500, 1000, 2000, 5000 ml
Neck
Narrow or wide; plain rim or ground-glass joint
Chemical resistance
Inert to most acids, alkalis and organic solvents
How It Is Used
The flask is a general vessel for heating, boiling and keeping liquids, and is common in chemical synthesis and preparation work. Because the base is flat, it can be filled and left standing on the bench or set on a heating plate without extra support.
Frequently Asked Questions
Does the Flat Bottom Flask need a cork ring or stand to stay upright?
No. Its flat base lets it stand independently on a laboratory bench or a heating plate.
What sizes does the Flat Bottom Flask come in?
It is made in 50, 100, 250, 500, 1000, 2000 and 5000 ml capacities.
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