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Why wouldn't it be sensible to put an ice cube in a vacuum flask?
Putting an ice cube in a vacuum flask may not be sensible because the vacuum flask is designed to keep contents at a certain temperature by reducing heat transfer, so the ice cube may not melt quickly or release its cooling effect effectively inside the flask. The vacuum insulated walls of the flask work to prevent heat exchange with the surroundings, so the ice cube may not provide the desired cooling effect when placed inside.
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.
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.
When the water level is higher inside than outside the flask is the gas pressure in the flask higher than lower than or the same as the atmospheric pressure?
When the water level is higher inside than outside the flask, the gas pressure in the flask is lower than the atmospheric pressure. This is because the weight of the column of water inside the flask creates an additional pressure on the gas inside, reducing its pressure relative to the atmospheric pressure outside.
Why was it necessary to match the water levels inside and outside the cooled flask before removing it from the water bath?
So to equalize the pressure inside the flask with that of the atmosphere.
Which form of heat transfer is reduced by the use of vacuum inside a vacuum flask?
The vacuum reduces both conduction and convection.
Why are the walls of the vacuum flask made from glass?
Glass is a good insulator, helping to maintain the temperature inside the vacuum flask. It is also transparent, allowing users to see the contents of the flask easily. Glass is also odorless and does not affect the taste of the liquids stored inside.
How does a vacuum flask reduce heat loss from a hot liquid inside?
Due to open space isolating the flask from external temperature
Why wouldn't it be sensible to put an ice cube in a vacuum flask?
Putting an ice cube in a vacuum flask may not be sensible because the vacuum flask is designed to keep contents at a certain temperature by reducing heat transfer, so the ice cube may not melt quickly or release its cooling effect effectively inside the flask. The vacuum insulated walls of the flask work to prevent heat exchange with the surroundings, so the ice cube may not provide the desired cooling effect when placed inside.
How does a vacuum flask reduce heat transfer?
A vacuum flask reduces heat transfer by creating a vacuum between two layers of insulated material, which minimizes conduction and convection. Additionally, the reflective lining inside the flask helps to reduce radiation heat transfer. This combination of insulated layers and reflective lining helps to maintain the temperature of the liquid inside the flask for a longer period of time.
Vacuum is mantained in thermos flask?
A vacuum is maintained in a thermos flask in order to prevent heat transfer by conduction and convection. The absence of air molecules in the vacuum reduces the amount of heat that can be transferred through these processes, helping to keep the contents of the flask hot or cold for longer periods of time.
Can a vacuum flask keep cold liquids cold?
Yes, a vacuum flask can keep cold liquids cold by creating a vacuum between two layers of insulating material, which helps to maintain the temperature of the liquid inside the flask. This insulation prevents external temperature changes from affecting the liquid inside, allowing it to stay cold for an extended period of time.
What is the function of the silvered surface in a vacuum flask?
The silvered surface in a vacuum flask helps to reflect heat back into the container, reducing heat transfer by radiation. This helps to maintain the temperature of the contents inside the flask by minimizing heat loss or gain.
Why is the inside of a vacuum flask shiny?
The inside of a vacuum flask is shiny because of the reflective metal coating, usually made of stainless steel. This shiny surface helps to reflect heat radiation, which helps to maintain the temperature of the liquid inside the flask.
Why are shiny outer surfaces needed in a vacuum flask?
The outer surfaces do not need to be shiny. The interior ones do, to reflect heat back rather than let the heat pass out of the vacuum flask. The vacuum between the double walls of the flask also reduces heat loss.
How does a vacuum flask keep things cold?
A vacuum flask keeps things cold by using a vacuum layer between the inner and outer walls of the flask to reduce heat transfer through conduction and convection. This prevents outside heat from reaching the contents inside, helping to maintain their temperature for a longer period of time.
explain how heat transfer can be minimised by convection in a vacuum flask?
Heat transfer by convection can be minimized in a vacuum flask because there is no air (or fluid) inside to carry heat through convection currents. The vacuum creates a barrier that reduces heat transfer by convection, as there is no medium for the heat to move through. This helps to keep the contents of the vacuum flask at their original temperature for a longer period of time.
