The vacuum space between the two silvered surfaces make efficient heat insulation against heat loss.
The flask works because there is a gap between the inner and outer walls of the flask. During the manufacturing process the air in the gap is extracted and the opening is sealed - creating a vacuum between the walls. Heat transmits rapidly through air - but a lot less rapidly, in fact only very, very slowly, through a vacuum. A vacuum flask not only keeps heat in, it also keeps it out. If you put iced water into a vacuum flask it will stay cold for a very long time.
An old instrument that works very well for solids and liquids is a pichnometer. It is a glass flask with a defined, exact volume and you determine the density by weighing the pichnometer full of water (known density at a specified temperature), the empty flask and the flask with a small amount of the solid or full of a liquid. Note: The liquid or solid should not dissolve in water. If the do, use a standard liquid of known density that will not dissolve the sample
A vaccum flask,since it can the temperature of it's content constant.
I would use to measure a volume of a glass liters. Signed Luini, liters are bigger than milliliters and liters are about the volume of a glass.
You would think so, but that would depend on what kind of glass you are using.
To see through :0
We all went on a picnic , and ate some food and had a hot drink from a thermos flask .
The plastic flask is needed for trace analysis on analytes at ppb levels that might be lost by adsorption on the glass surface.
You should always be cautious when heating chemicals in a flask. The glass flask containing phosphoric acid was soon leaking its contents onto the floor.
A thermos is able to do what it does by using a several of physical and material properties to keep our hot chocolate hot and our ice tea icy. A thermos has an inner container made of glass. This container is really like one bottle inside of another bottle and sealed at the ends by melting the edges together. The air is removed out from the space between the two bottles to produce a vacuum, which is not a good conductor of heat and does a good job at slowing down the movement of heat. To slow down the other heat they coat the facing surfaces of the glass bottles with a silvery coating (like a mirror). This reflects the heat and helps slow down any losses that might get that way. They use a material like cork or rubber to make the bottle stopper and anything else that might touch the outside surface of the glass container. These materials are bad conductors of heat and slow down the heat loss. What's left is what we can see on the outside which can be metal or plastic and is the covering for the glass bottles. The idea here (with the thermos) is to slow down the movement of heat from one place to the other. So if you have hot stuff in the thermos or cold stuff in the thermos, the end result is the same. Keep heat from moving to where you don't want it to go for as long as possible. NB It's worth mentioning that modern vacuum flasks (Thermos being a trade name) are made almost entirely of stainless steel, inside and out - it doesn't shatter and is naturally reflective, although not polished to a mirror shine when used as a flask inner. Modern stoppers are also made of plastic.
This is from wikipedia:The vacuum flask was invented by Scottish physicist and chemist Sir James Dewar in 1892 and is sometimes referred to as a Dewar flask after its inventor. The first vacuum flasks for commercial use were made in 1904 when a German company, Thermos GmbH, was formed. Thermos, their trademark for their flasks, remains a registered trademark in some countries but was declared a genericized trademark in the U.S. in 1963 as it is colloquially synonymous with vacuum flasks in general.
The flask makes use of heavy insulation, either by vaccum, air cushion or just filled with very poor heat conductors to slow the heat loss from a hot drink or warming from the enviroment.
A thermos flask is not meant to be eaten. It is designed to keep food and drinks hot or cold for an extended period of time. To use a thermos flask, simply open the lid, pour in your desired food or drink, seal the lid tightly, and enjoy your hot or cold item when desired.
He didn't. He used a Dewar or vacuum flask. It is used to keep things hotter or colder than the surrounding ambient temperature. He failed to patent the idea and it was subsequently patented by Thermos. Thermos is still a registered trade mark in many countries, though it has been declared generic in the US.
The best way to do so be be to use a good thermal insulator. A thermos flask would suit this purpose.
my thermos was full with ice cold water.
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.