Boiling Flasks Singapore: Round-Bottom Flask Buying Guide
The boiling flask — almost always a round-bottom flask — is the vessel at the heart of distillation, reflux and synthesis in chemistry laboratories. Whether a quality-control lab in Singapore is distilling solvents for purity checks, a university teaching lab is running reflux reactions, or a research group is concentrating samples on a rotary evaporator, the round-bottom flask does the heavy lifting.
At JW RESEARCH SUPPLY, we supply borosilicate 3.3 boiling flasks from 50 mL to 5000 mL, in single-neck and multi-neck configurations with standard taper joints, to laboratories, schools and testing houses across Singapore. This guide covers shapes, capacities and neck options so you order the right flask the first time.
Boiling Flask Specification Overview
| Capacity | Neck Joint | Typical Use | Configuration |
|---|---|---|---|
| 50 – 100 mL | 14/23 | Rotary evaporation, small-scale reactions | Single / two-neck |
| 250 – 500 mL | 24/40 | Standard reflux and distillation | Single / three-neck |
| 1000 mL | 24/40 | Preparative synthesis, larger distillations | Three-neck |
| 2000 – 5000 mL | 29/32 | Pilot and process-scale work | Three-neck / four-neck |
Round-Bottom vs Flat-Bottom vs Erlenmeyer
| Feature | Round-Bottom Flask | Flat-Bottom / Erlenmeyer |
|---|---|---|
| Heating evenness | Excellent — mates with mantles and baths | Good on hot plates only |
| Vacuum resistance | High (no flat face to collapse) | Low — avoid vacuum use |
| Stands unsupported | No — needs clamp or flask ring | Yes |
| Best applications | Distillation, reflux, rotavap, synthesis | Storage, media prep, titration |
Key Features to Check When Ordering
- Glass quality — Borosilicate 3.3 glass gives thermal shock resistance, chemical durability and safe autoclaving; look for consistent wall thickness and fire-polished rims.
- Neck joint — Standard taper joints (14/23, 24/40, 29/32) must match your condensers, still heads and adapters. Jointed necks seal grease-free with a joint clip.
- Number of necks — Count the necks you actually need: one for a condenser, extra necks for thermometers, addition funnels and stirrers. Side necks at 45° angles keep lines clear of the centre joint.
- Pear-shaped option — For rotary evaporators, pear-shaped (Büchi-style) flasks reduce surface area and give better mixing of small volumes.
- Heavy-wall or graduated — Heavy-wall flasks resist vacuum work; a graduation mark on larger sizes helps you judge recovered volumes during distillation.
Care, Cleaning and Safe Handling
Rinse boiling flasks immediately after use, wash with a neutral laboratory detergent and rinse with deionised water, then dry in a rack or oven below 150°C. Never heat a closed flask — always vent through the open joint — and always support round-bottom flasks with a clamp on the neck plus a heating mantle or flask ring. Add boiling chips or a magnetic stir bar before heating to prevent bumping, and never pour cold solvent into a hot flask or cool a hot flask on a cold surface. Inspect routinely for star cracks and scratches, which weaken the glass under vacuum and thermal stress.
Why Choose JWRESEARCH for Boiling Flasks in Singapore?
- Full range — 50 mL to 5000 mL, single to four-neck, with matching condensers, still heads and stoppers.
- Borosilicate 3.3 quality — Annealed, consistently walled glassware you can autoclave and trust under vacuum.
- Interchangeable joints — Standard taper joints that fit the rest of your glassware kit.
- Fast local delivery — Quick dispatch across Singapore with breakage-safe packing.
JWRESEARCH supplies boiling flasks, condensers, still heads and general laboratory glassware to schools, universities, research institutes and QC laboratories across Singapore. Contact us for capacities, neck configurations and bulk pricing.
📞 +65 8039 3660 | ✉️ SINGAPORE@JWSHY.COM
🌐 www.jwresearch.cn
Frequently Asked Questions
Q: What is a boiling flask used for?
A boiling flask, normally with a round bottom, is used to hold liquids that are heated to boiling for distillation, reflux, synthesis and rotary evaporation. The round shape gives even heating and has no corners where material can trap and overheat, which makes it the standard vessel for organic reactions and for distilling solvents and reaction mixtures.
Q: Round-bottom or flat-bottom flask — which should I choose?
Choose round-bottom flasks whenever the vessel will be heated strongly, stirred or connected to a condenser, because the curved base distributes heat and mechanical stress evenly and mates with heating mantles. Flat-bottom flasks and Erlenmeyer flasks are cheaper and stand on their own, so they suit storage, media preparation and gentle heating on a hot plate, but they should not be used under vacuum or for vigorous reflux.
Q: Can boiling flasks be autoclaved and heated safely?
Borosilicate 3.3 boiling flasks can be autoclaved at 121°C and used up to about 500°C for brief periods, but never heat a flask that is closed, dry or cracked. Use a heating mantle, water bath or sand bath rather than a bare flame, add boiling chips or a stir bar before heating, and clamp the flask firmly by the neck with the joint vented to the atmosphere.
Q: Single-neck, two-neck or three-neck — how many necks do I need?
Single-neck flasks are enough for distillation, reflux and rotary evaporation where the condenser occupies the neck. Two-neck and three-neck flasks let you insert a thermometer, dropping funnel, stirrer shaft or inert-gas line at the same time, so they are preferred for reactions that need addition and temperature monitoring while the condenser is mounted in the centre neck.