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Discounting any ridiculous side-usage for rubber stoppers that may exist, they are simply used to seal glasswear in a temporary manner.
For example, if you want to shake your solution but don't want to get it all over yourself. Or if you want to transport it and minimize risk of spillage.
We generally don't use rubber stoppers much anymore, though. Glass stoppers are considered safer since they will pop out more easily if pressure builds inside the glasswear (which can be VERY dangerous). I would never stopper anything that I am applying heat to or that I expect gas production from, so be careful in your usage.
Glass stoppers are also a little better because you know if your solution isn't reacting with your glasswear, it won't react with the stopper....whereas it may still react with a rubber stopper.
Another advantage is that glass stoppers are easier to remove (try greasing them if they leak air or don't work smoothly). A good example is if you are using a separating funnel you will usually want to shake the funnel and then relieve the pressure by removing the stopper (at very regular intervals). This can be a pain with a rubber stopper as they require more force, which can also lead to accidents. Again, glass stoppers make this much easier.
Cork stoppers are used similarly.
The easy answer is, "to cap test tubes and flasks." The real answer is, rubber stoppers are used in the lab because the rubber in them is unaffected by most chemicals - and unlike the glass stoppers that used to be standard in laboratories, they don't get stuck in the container.
To keep things in flasks. Glass is less reactive than rubber, and some corrosive chemicals will eat right through the rubber!
Stoppers placed in the mouths of flasks and test tubes prevent spillage and evaporation.
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What size rubber stopper fits in a 1000 ml Erlenmeyer flask?
Size 8.
Why an Erlenmeyer flask containing a hot solution is not tightly stoppered?
Because... if it's tightly sealed - during cooling the volume of the solvent will decrease - making the pressure inside lower than outside he flask. This could be enough for the glass to shatter - spilling the contents.
What is a piece of cork?
Rubber corks are commonly used in labs with test tubes as a stopper. The rubber corks are used on flask as well. The function of the rubber cork is to keep the contents in the container.
What is stopper in the thermos?
Its reduces evaporation, and something else i dont know! :)
What is a bung used for in science?
to plug your bunghole, which is the hole in the side of a barrel or on top of a flask. AKA rubber cork.
A flask fitted with a stopper that is used in the preparation of solution?
volumetric flask
What stoppers a flask?
Normally cork or rubber is used as a stopper in a flask.
What is the use of iodine flask?
An Iodine Flask is essential an Erlenmeyer Flask with a stopper used for the wet chemical analysis "Iodine Determination" . This analysis is typically performed on fatty acids, oils and shellac varnishes.
What size rubber stopper fits in a 1000 ml Erlenmeyer flask?
Size 8.
What is used to seal the top of a test tube or flask?
A stopper or cap is typically used to seal the top of a test tube or flask. It helps prevent contamination and evaporation of the contents inside. Stopper materials can vary from rubber to plastic depending on the application.
Why an Erlenmeyer flask containing a hot solution is not tightly stoppered?
Because... if it's tightly sealed - during cooling the volume of the solvent will decrease - making the pressure inside lower than outside he flask. This could be enough for the glass to shatter - spilling the contents.
How does a tight fitting plastic stopper on a flask minimise heat transfer?
A tight fitting plastic stopper on a flask reduces heat transfer by minimizing air flow into and out of the flask. This helps to maintain the temperature of the contents inside the flask by preventing heat exchange with the surrounding environment.
Why there is a exchange of heat in a thermos flask after 2hours?
Because - even though the vacuum between the layers of the flask is almost perfect, the junction between the flask and its stopper creates a 'weak spot' where a small amount of heat can escape over time.
What is the function of the erlenmeyer flask?
The Erlenmeyer flask was named after its creator Emil Erlenmeyer, who was a German chemist. It is a flat bottomed cone-shaped container that has a tapered neck so that a person can hold it, put a stopper on it or attach a clamp with it. This flask is used to measure, mix, and store liquid.
How does the structure of a vacuum flask minimise energy transfer?
The vacuum between the two layers cannot conduct heat.The silvering on the inside reflects heat back to the contents.The stopper prevents heat loss by convection.The stopper is made of poor thermal conductors.
What is mean by open topped glass flask?
An open-topped glass flask is a container made of glass that has an opening at the top without any stopper or lid. This design allows for easy access to the contents inside the flask, but it also means that it is not suitable for storing substances that need to be kept airtight or secure from contamination.
Individual pictures of laboratory apparatus?
dropper stopper triangle tongs tripod florescent flask beaker mortal and pestle filter funnel evaporating dish
