Quick Answer: A narrow mouth reagent bottle is a laboratory storage bottle with a small neck opening, normally closed by a stopper, used to store liquid reagents and pour them in a controlled stream. The narrow neck limits evaporation and spillage compared with a wide-mouth bottle.
Why Liquids Go in Narrow-Necked Bottles
Liquids are poured, not scooped, so a liquid reagent does not need a wide opening. The narrow mouth reagent bottle takes advantage of that. Its small neck gives a thin, steerable stream when pouring into a beaker or measuring cylinder, and the small exposed surface means less evaporation of volatile liquids such as ethanol or dilute ammonia solution, and less moisture pick-up by hygroscopic liquids like concentrated sulfuric acid.
This listing does not name the bottle material or colour, and LabEquip lists a clear-glass version separately as the Reagent Bottle, Narrow Mouth (Clear Glass). Narrow-mouth reagent bottles are generally made in clear glass, in amber glass for light-sensitive solutions, or in plastics such as polyethylene and polypropylene, so state which you need when ordering.
The choice matters chemically. Amber glass protects silver nitrate and potassium permanganate solutions from light; plastic is required for hydrofluoric acid, which dissolves glass; and glass is preferred for most organic solvents. Many school reagent shelves are organised as one set of narrow-mouth bottles in mixed materials, each matched to its contents.
Applications
- Bench reagent sets for qualitative analysis, one bottle per test solution
- Storing dilute acids and alkalis for school practicals
- Keeping volatile liquids such as ethanol with little evaporation between lessons
- Holding light-sensitive solutions when an amber version is chosen
Specifications
| Item | Reagent bottle with a narrow neck for liquids |
| Neck | Narrow mouth for controlled pouring and reduced evaporation |
| Suited contents | Liquid reagents: dilute acids, alkalis, salt solutions, solvents |
| Related listing | Clear-glass version listed separately |
| Material, colour, closure and capacity | Confirm at enquiry |
Care & Handling
- Keep glass stoppers out of bottles of sodium hydroxide or other alkalis; alkali creeps into the ground joint and cements the stopper. Use a rubber or plastic closure instead.
- Hold the bottle with the label towards your palm when pouring, so drips run down the unlabelled side.
- Set a removed stopper down on its flat top, never on its tapered side, so it does not pick up contamination from the bench.
- Never return unused reagent to the bottle; pour out only what you need.
Why Choose LabEquip
School and college chemistry departments buy narrow-mouth bottles in sets to stock reagent shelves and side-bench kits. LabEquip keeps them in the Chemistry Lab Equipments category alongside wide-mouth bottles for solids; send the material, colour and sizes required through the contact page.
Frequently Asked Questions
What is the difference between a narrow mouth and a wide mouth reagent bottle?
The narrow mouth bottle is meant for liquids, which pour in a controlled stream through a small neck and evaporate less. A wide mouth bottle is meant for solids such as crystals and pellets, which need to be scooped out with a spatula.
Which reagents need an amber bottle?
Solutions that decompose in light, such as silver nitrate, potassium permanganate, iodine solutions and hydrogen peroxide, are normally kept in amber glass. Clear bottles are fine for most acids, alkalis and salt solutions kept away from direct sunlight.
Can hydrofluoric acid be stored in a glass reagent bottle?
No. Hydrofluoric acid attacks glass, so it must be kept in a bottle made of a resistant plastic such as polyethylene. Concentrated alkalis also etch glass slowly over long storage.
Why is my glass stopper stuck?
Stoppers usually seize when alkali or dried salt solution gets into the ground joint. Try warming the neck gently in warm water and tapping the stopper with a wooden block. Do not force it with pliers, and wear gloves and eye protection.
How do I prevent contamination of stock reagents?
Pour a small amount into a clean beaker and work from that, rather than dipping a pipette or dropper straight into the stock bottle. Any portion left over is discarded, not poured back.
What should I specify when ordering?
Give the capacity, the material or colour you want (clear glass, amber glass or plastic) and the closure type, along with quantities. LabEquip can then say which version is supplied against this listing.
Last Updated: September 2026
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