Name: Round-Bottom Flask
Brand: RichTech

Specifications

Round-Bottom Flask · Specifications

Standard capacity ranges below. Custom capacities and special specifications available upon request.

Capacity (mL)	O.D. (mm)	Height (mm)	Neck I.D. (mm)	Joint Size
50	51	86	21	14/23
100	64	105	24	19/26
150	72	118	26	19/26
250	82	140	30	24/29
500	102	175	36	24/29
1000	130	225	42	29/32
2000	166	280	50	29/32
3000	190	320	55	34/35
5000	230	380	62	34/35
4000	—	—	—	—
6000	—	—	—	—
10000	—	—	—	—
15000	—	—	—	—
20000	—	—	—	—
50000	—	—	—	—

* Custom capacities and special specifications available. Contact us for details.
* Round-bottom flasks feature standard ground joints for compatibility with condensers and other accessories.
* Recommended for use with heating mantles or oil baths — consult our sales team for proper sizing.

Product Description

The round-bottom flask is an essential vessel for organic synthesis and distillation in the laboratory, featuring a round bottom that provides even heat distribution. The narrow mouth reduces evaporation and splashing. Requires a heating mantle or oil bath for safe and efficient heating.

Four Series · Flexible Selection

RichTech offers flasks in Erlenmeyer, Filtering, Round-Bottom, and Flat-Bottom series:

1. Erlenmeyer Flasks (Standard Conical)

Conical design with wide base and narrow mouth for easy mixing and storage.
Narrow mouth effectively reduces evaporation and splashing, ideal for titration.
Suitable for titration analysis, heating reactions, and media preparation.

2. Filtering Flasks (Side-Arm)

Features a side-arm for connection to a vacuum pump for filtration.
Uniform wall thickness to withstand vacuum pressure.
Used with Buchner or fritted funnels for solid-liquid separation.

3. Round-Bottom Flasks

Round-bottom design for even heat distribution, ideal for reflux and distillation.
Requires heating mantle or oil bath — not for use on hot plates.
Used in organic synthesis, reflux reactions, and distillation.

4. Flat-Bottom Flasks

Flat bottom for stable placement on hot plates or workbenches.
Combines the narrow mouth of a flask with the stability of a beaker.
Suitable for heating reactions, solution preparation, and general storage.

Design Features

Round Bottom: Provides even heat distribution, ideal for reflux and distillation operations.
Narrow Mouth: Reduces evaporation and contamination during extended heating.
Standard Joint: Compatible with condensers, distillation heads, and other accessories.
Uniform Wall Thickness: Minimizes thermal stress during heating, reducing the risk of breakage.

Material Advantage

Manufactured from Borosilicate Glass 3.3 in accordance with ISO 3585 standards. The ultra-low coefficient of thermal expansion (3.3×10⁻⁶/K) ensures resistance to thermal shock up to 280°C, making it suitable for heating, cooling, and a wide range of laboratory operations.

Quality Assurance

Every piece undergoes rigorous dimensional inspection, stress testing, and visual inspection to meet high laboratory standards, providing reliable performance for your experiments.

Note: Round-bottom flasks must be used with a heating mantle or oil bath — never place directly on a hot plate. Ensure the flask size matches the heating mantle. Install a condenser for reflux operations to prevent solvent loss.

Applications

Common Configurations

Heating Mantle/Oil Bath + Flask Even heating, reflux reactions
Reflux Condenser + Flask Heating reflux, solvent recovery
Distillation Head + Flask Atmospheric/vacuum distillation
Stir Bar + Flask Magnetic stirring reactions

Specific Applications

Organic Synthesis

Pharmaceutical intermediates, fine chemical synthesis

Heating Reflux

Extended heating reactions with condenser for solvent recovery

Atmospheric Distillation

Separation and purification of liquid mixtures

Vacuum Distillation

Distillation of high-boiling or heat-sensitive materials

Solvent Recovery

Recycling solvents after reactions

Extraction

Liquid-liquid extraction operations

Teaching Labs

Organic chemistry laboratory instruction

Pharmaceutical R&D

Drug synthesis process development

Tip: Round-bottom flasks are particularly well-suited for reflux and distillation operations due to their round-bottom design for even heat distribution. Always use with a heating mantle or oil bath — never place directly on a hot plate for safe and efficient heating.

Flask Procedure

03

Heating

Round-bottom flasks must be used with a heating mantle or oil bath — never place directly on a hot plate or open flame.
Select a heating mantle that matches the flask size for proper fit and heat transfer.
For oil bath heating, ensure the oil level is above the liquid level inside the flask for even heating.
Do not fill the flask beyond 2/3 of its capacity to prevent boiling over during heating.
Install a reflux condenser for reflux operations to prevent solvent loss.
When heating liquids, do not point the flask opening toward yourself or others to prevent injury from splashing.

04

Reflux & Distillation

For reflux, install the condenser vertically — cooling water flows in from the bottom and out from the top.
For distillation, connect the distillation head to the condenser and collect fractions at the receiver end.
For vacuum distillation, apply vacuum gradually to prevent bumping.
Ensure cooling water flow during distillation for efficient condensation.

05

Stirring & Mixing

For magnetic stirring, select a stir bar that matches the flask size and place it in the flask before adding liquid.
For mechanical stirring, use a stirrer adapter through the ground joint.
Adjust stirring speed to prevent splashing.

06

Cleaning & Maintenance

Clean promptly after use to prevent residue from drying and hardening.
Use dilute acid or specialized cleaning agents for stubborn residues.
Rinse with distilled water and air-dry upside down on a drying rack.
Due to the round bottom, pay extra attention to cleaning the bottom interior.
Store carefully to avoid chipping and breakage.

Tip: Round-bottom flasks are essential tools for organic synthesis and distillation operations. Proper heating methods and accessory selection are critical for experimental success. Clean and dry thoroughly after each use to extend product life.

Care & Notes

Show care & notes

Safety Notes

Inspect flasks for cracks or scratches before use — damaged glass may break when heated.
For reflux and distillation, ensure secure connections to prevent leaks.
For vacuum distillation, apply vacuum gradually to prevent bumping and backflow.

Do not

Round-bottom flasks must be used with a heating mantle or oil bath — never place directly on a hot plate.
When heating liquids, do not point the flask opening toward yourself or others.
Do not place hot flasks directly into cold water — thermal shock may cause breakage.
Handle and store with care, avoiding impact with hard surfaces.