Chapter 10 Flashcards
(9 cards)
What is thermal contact, thermal equilibrium, temperature, and heat?
Thermal contact- two object are in thermal contact of energy can be exchanged between them
Thermal equilibrium- two objects are in thermal equilibrium if they are in thermal contact and there is no net exchange of energy
Temperature- relates to the exchange of energy between objects that are in thermal contact
Heat- exchange of energy between two objects because of differences in their temperatures
What is the zeroth law of thermodynamics?
If 2 objects are in thermal equilibrium with a third object, then the 2 are in thermal equilibrium with eachother
2 objects in thermal equilibrium with each other are at the same temp
Slide 5 March 12
How do each of these thermometers measure temperature?: Liquid in glass thermometer Platinum resistance thermometer Thermocouple thermometer Constant volume thermometer
Liquid in glass- based on thermal expansion of the liquid
Platinum resistance- based on dependence of resistivity on temperature
Thermocouple- based on a temperature difference causing electric potential difference
Constant volume- based on dependence of pressure on temperature
Slides 7-9 March 12
What is the difference between Celsius and Fahrenheit?
Celsius- freezing point of water at 1 atm is 0C
Boiling point of water is 100C
Fahrenheit- freezing point of water at 1atm is 32F
Boiling point of water is 212F
Tc = (5/9)(Tf-32)
What is the unusual behaviour of water?
Max density, water in lake
Max density of water occurs at 4C
As water cools from temperatures above 4C it increases in density and sinks. As a result, warmer water floats to the surface, cools, and sinks
The upwelling process stops at 4C
As water cools from 4C to 0C, it expands and stays at the surface and eventually freezes. Water at bottom of lake is at 4C
What is an ideal gas?
Collection of atoms or molecules that exert no long range forces on each other
Each particle of an ideal gas is point like, occupying a negligible volume
One mole of gas contains Avogadro’s number of particles
n= m/molar mass
m= molar mass/ Avogadro’s number (Na)
What is Charles law, gay lussacs law, Boyle’s law, and Avogadro’s law?
What is the ideal gas law from these above laws?
Charles law- V~T
Gay-Lussac’s law- P~T
Boyle’s law- P~1/V
Avogadro’s law- V~N
PV=nRT
Microscopic- PV=N(kb)T
P1V1/T1=P2V2/T2
P is absolute pressure!!
T is kelvins!!
What is the kinetic theory of gases?
The microscopic theory based on treating the gas molecules as point like particles that move independently and only interact via collisions
Good approximation for dilute gases under ordinary conditions
Slide 3 March 14
How is the change in momentum and average force on wall due to each molecule found with molecules in gas?
Δp= m|Δvx| = 2m|vx|
Δt=distance/speed=2d/|vx|
Fav=|Δp|/Δt = 2m|vx| / (2d/|vx|) = m|vx|^2 / d
Slide 4-7 March 14
F= N = Nm/d P=F/d^2 = Nm/d^3 = Nm/V
