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1. Silvered interior reflects any heat which may transfer though radiation
2. Moderately hard vacuum almost eliminates transfer by conduction (& convection though this would be modest anyway)
3. Vacuum bottle is only supported by a few small rubber pads - again limiting conduction
4. Cap designed with air gaps to reduce conduction: plastic/air/plastic/air/plastic
5. Most flasks have an outer of plastic which is a reasonable insulator against conduction heat loss.
The vacuum itself is the most significant design point.
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∙ 11y ago
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Why wouldn't it be sensible to put an ice cube in a vacuum flask?
When water freezes becoming ice it expands. In a vacuum flask as ice melts it will contract. This will cause the flask to crack.
The color of a vacuum flask in the inside?
white
What is a Buchner or filter flask and how is it used?
From Wikipedia.com (see Link to the left):A Büchner flask, also known as a vacuum flask, filter flask, side-arm flask or Kitasato flask, is a thick-walled erlenmeyer flask with a short glass tube and hose barb protruding about an inch from its neck. The short tube and hose barb effectively acts as an adapter over which the end of a thick-walled flexible hose (tubing) can be fitted to form a connection to the flask. The other end of the hose can be connected to source of vacuum such as an aspirator vacuum pump or house vacuum. Preferably this is done through a trap (see below), which is designed to prevent the suckback of water from the aspirator into the Büchner flask.See the Web Links and Related Questions to the left for more information.
How do you deal with the liquid mercury scattered in laboratory?
Set up a vacuum flask with flexible intake tubing long enough to reach the mercury spill. Use glass tubing on the inside of the flask to reach nearly to the bottom on the intake side. On the other side (the side connected to the vacuum source) make sure the glass tubing reaches just inside the flask, near the top, so that the mercury entering the flask will not simply be sucked into the vacuum source lines. Use a two-holed rubber stopper to accomplish all this. This will give you a mercury vacuum cleaner, so to speak. Use a regulator and be careful to use just enogh vacuum to lift the mercury into the flask.
Is heating a flask on a hot plate an example of activation energy beginning to react?
No, heating a flask on a hot plate is not an example of activation energy beginning to react. Activation energy refers to the minimum amount of energy required for a chemical reaction to occur, and it is not related to heating a flask. Heating a flask on a hot plate simply refers to the process of applying heat to the flask, which can facilitate a reaction by increasing the temperature and providing the necessary energy for the reaction to proceed.
Vacuum is mantained in thermos flask?
The vacuum reduce heat loss by conduction and convection.
How does a vacuum flask keep tea hot?
Insulation
What is the name of the thing used to keep liquids warm or cold?
Vacuum flask.
What Vacuum flask keeps liquid at same temperature?
There is no way to permanently store heat. The most you can expect, from a high-quality vacuum flask, is to keep the liquid cold, or hot, for a fairly long time. But gradually, some heat will seep in, or out, until the temperature in the vacuum flask will be equal to the temperature of the surroundings.
How can the structure of the vacuum flask minimise energy transfer by conduction convection and radiation?
The flask has a double wall, with no air between the two walls (vacuum)- conduction. The walls are highly reflective silver- radiation. the flask has a small beck that is closed by a stopper or cap-convection.
How does a vacuum flask reduce the rate of energy transfers?
Conduction and convection are reduced by the vacuum between the two glass layers.Radiation is reduced by the mirror plating.
What is vacuum cup?
it is the cup that comes on a vacuum flask
Substance that contains the vacuum in a vacuum flask?
Glass
What is silvering in a vacuum flask?
There is a silvering in the vacuum flask in order to reduce the loss of heat through the means of radiation.
Why are vacuum flasks called vacuum flasks?
why are vacuum flasks called vacuum flask
How does a themos flask work?
Also known as a Buchner or vacuum flask, the flask uses vacuum to filter samples. A vacuum hose is attached to the hose barb and the funnel is placed on top. As the hose creates a vacuum, the sample is filtered through the funnel.
How is heat transferred away from a vacuum flask?
a vacuum flask is not 100% vacuum. it contains some particles or gas molecules which absorbs a small amount of heat.
