Difference between revisions of "Thermometry pchem lec"

Revision as of 13:05, 28 August 2020

Thermometry: measuring temperature.

Q1: What is temperature? Just a number?

A1 - the degree or intensity of heat present in a substance.

A2 - a measurement of the average kinetic energy of a particle in a system; 3/2kT <--per molecule

Q2: How do we measure temperature?

A1 - Most commonly we use a thermometer.

Temper is never measured...we measure other system variable and then relate this back to temperature/average kinetic energy of the particles.

- Most common is change in volume as a function of changes in temperature

- changes is voltage as a function of changed in temperature [thermocouple, used for measuring very hot (flames/kiln) environments]

- changes is color as a function of changed in temperature (thermochromic)

- changes is pressure as a function of changed in temperature (used to develop the idea of an absolute zero, zero pressure zero temperature.)

- IR light emission (intensity/wavelength) as a function of temperature

@@ Line 8: / Line 8: @@
 :A1 - Most commonly we use a [[Media:The Thermometer.pdf|thermometer]].
 [[File:temperature_scale.jpg|400px]]
+Temper is never measured...we measure other system variable and then relate this back to temperature/average kinetic energy of the particles.
+:- Most common is change in volume as a function of changes in temperature
+:- changes is voltage as a function of changed in temperature [thermocouple, used for measuring very hot (flames/kiln) environments]
+:- changes is color as a function of changed in temperature  ([https://en.wikipedia.org/wiki/Thermochromism thermochromic])
+:- changes is pressure as a function of changed in temperature (used to develop the idea of an absolute zero, zero pressure zero temperature.)
+:- IR light emission (intensity/wavelength) as a function of temperature