Thermos flasks are designed to hinder heat transfer between the liquid placed within them and the surrounding environment. The insides and outsides of flasks are often silvered to impede heat transfer through radiation. The interior of the flask is also made of a thermal insulator to impede heat conduction.Know More
A thermos flask prevents heat transfer through conduction and convection using a partial vacuum between two containers, one placed within the other. This partial vacuum impedes the transfer of thermal kinetic energy between the molecules within the flask and those outside it, making it suitable for keeping chilled drinks cold and hot drinks warm. The inner flask is often made from borosilicate glass of low thermal conductivity to further aid in preventing conduction. Flasks may also feature a silver coating that prevents heat transfer through infrared radiation.
The original vacuum flask was invented by Sir James Dewar in 1892. The Dewar flask was similar to the modern design, consisting of two flasks placed one within the other, with contact only at the neck. Dewar’s original design was made to keep palladium samples at a constant temperature to facilitate calorimetry measurements. In 1904, Dewar’s design was commercialized by German glassblowers, who renamed the flask Thermos.Learn more about Thermodynamics
Boiling can be considered as a cooling process because as a liquid reaches its critical temperature, heat escapes through rapid evaporation. Essentially, boiling happens when liquids turn into gases, forcing excess heat out of the liquid.Full Answer >
According to Elmhurst College, the molecules in a liquid are packed closely together and make random movements, as the molecules slip past each other. As the liquid is heated, the kinetic energy increases, which causes the motion of the molecules to increase. Eventually, the motion becomes so intense that the forces of attraction between the molecules are disrupted, and the molecules break free of the liquid, becoming a gas.Full Answer >
Conduction is heat transfer through solid objects, while convection is heat transfer through liquid or gasses. Conduction and convection are both forms of radiation, which is heat transfer.Full Answer >
Energy is required to boil a liquid in order to give the molecules enough energy to overcome intermolecular attraction forces. While boiling, the highest energy liquid molecules are able to escape the liquid and enter the gas phase.Full Answer >