When we carry out experiments in chemistry and we need to measure the temperature of a solution, it appears to help us in the process. We are talking about the thermometer, a device well known by the sick with fever, but now we will see another purpose of this useful device: to measure the temperature of chemical reactions.
When reactions take place hot, that is, under high temperatures, a high degree of particle agitation occurs, causing the reaction to accelerate. In this case, the temperature is a catalyst for the reaction and it is often necessary to record it for further calculations, so we use so-called laboratory thermometers. They consist of a thin graduated glass tube that contains a liquid-filled bulb, which, under the effect of heat, this thermometric liquid expands by capillarity.
The chemical element used in these devices is mercury, as it is the only liquid metal, (liquid in the temperature range of -38.9°C to 356.7°C). Mercury expands as it is heated, and so it moves along the thermometer tube determining the temperature.
It is worth remembering that a laboratory thermometer is made with a special glass that allows the device to be immersed in liquids at high temperatures without breaking. That is why it is possible to measure the temperature of solutions above 100°C, for example. Through this same device we can know the melting temperature of solids such as tungsten, tantalum, iridium that have high melting points.
The graduation of the laboratory thermometer tube allows you to visualize the temperature variation in the Celsius and Fahrenheit scales, despite the Celsius being the most used.
By Líria Alves
Graduated in Chemistry
Brazil School Team
Do not stop now... There's more after the advertising ;)
See more!
look at the temperature - learn the correct way to use the thermometer.
Would you like to reference this text in a school or academic work? Look:
SOUZA, Líria Alves de. "How to measure the temperature of a solution?"; Brazil School. Available in: https://brasilescola.uol.com.br/quimica/como-medir-temperatura-uma-solucao.htm. Accessed on June 28, 2021.
