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
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 >
Melting point is the temperature at which a solid melts to become a liquid. Since water is already a liquid, it does not have a point at which it liquefies. Frozen water is called ice and has a normal melting point of zero degrees Celsius, according to Purdue.Full Answer >
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 >
The liquid in a glass thermometer, either colored alcohol or mercury, expands as it heats and condenses as it cools. In a thermometer, the liquid cannot expand outward and the only place it can go is up or down. Temperature on a glass thermometer can be measured in Fahrenheit, Celsius or Kelvin.Full Answer >