L1-L2 Flashcards
A set of characteristically quantitative approaches to the study of chemical problems
physical chemistry
Thermodynamics explains ____ reactions occur (aka the ____ ___ of the reactions) and the ____ a reaction generates or requires
why, driving force, energy
Gases form the ___ ___ of many machines (e.g. heat engines and ____). The gas phase is the ____ state of matter to treat theoretically, and it shows ____ behaviour that is _____.
working substance, refrigerators, simplest, limiting, universal
The ___ of a system is defined by a particular set of properties such as ___, ___, and ___. These properties can be related by an algebraic expression called an equation of state, such as the ___ ___ ____
state, temperature, volume, moles, ideal gas law
Ideal gas assumes that the gas molecules do not occupy any ____, and there are no ____ between the gas molecules
volume, interactions
The ideal gas law can describe many gasses at high _____ and low ____
temperature, pressures
A molecular interpretation of the ideal gas law that leads to a relation between internal energy and temperature
kinetic model of gasses
Assumptions for the kinetic model of gasses are that a gas consists of molecules in _____ motion, gas molecules are _____ ____ points, the molecules move in ____ ____ until they collide, and the molecules do not ____ except during collisions
random, infinitesimally small, straight lines, interact
In the kinetic model of gasses, the pressure arises from the force exerted on the ____ of the container when the impacting molecules are _____. We need to know the ___ of each impact and the number of impacts in a given interval. We find that the average ___ ___ ___ of one mole of an ideal gas, in other words the ___ ___, is only dependent on ____
walls, deflected, force, translational kinetic energy, internal energy, temperature
The equipartition principle states that each translational and ____ degree of freedom contributes _____ to the total energy, and each vibrational degree of freedom contributes ______ to the total internal temperature.
rotational, RT/2, RT
Rigid, diatomic molecules have _______, because there are ___ translational, ___ vibrational, and ___ rotational degrees of freedom. However, at room temperature, the ___ ____ ___ is not reached for ______ energy, thus it is not ____. This makes the internal energy of one mole of diatomic molecule, to be ____ at room temperature
U = 7/2RT, 3, 1, 2, high temperature limit, vibrational, excited, U = 5/RT
A monoatomic molecule only has ___ degrees of ____ freedom
3, translational
In real gasses, the ____ ___ of the molecules and the ____ between them lead to deviations from the ideal gas law. Consequently, the internal energy is no longer a function of ____ alone.
finite size, interactions, temperature
The repulsive interaction between molecules (aka the ___ ___), implies that they cannot come closer than a certain ____. The actual volume in which the molecules can move is thus _____ compared with the volume of the container V. Therefore, replace V in the ideal gas law by _____, where b is the volume / ___ occupied by the gas itself
size effect, distance, reduced, V-nb, mole
The energy of ___ one molecule experiences from the other molecules is proportional to the density, n/V. The total energy of attraction is thus proportional to ____. These forces ___ the pressure that the gas exert, and since pressure is energy per volume, the resulting change in pressure is proportional to _______. Thus, the pressure in the ideal gas law is replaced by ______
attraction, (n n/V), reduce, (n^2/v^2), P + a(n^2/v^2)
The compressibility factor is _______. the value is __ for an ideal gas
z = pV/nRT, 1
The virial equation shows that at ____ pressures, one often observes a ___ ___ of z with pressure. This linear behaviour can be described by the first two terms in the general virial equation: ____
moderate, linear dependence, z = PV/nRT = 1 + B2p (P)
The. virial equation is a series _____ in terms of pressure or an ____ power of molar volume, Vm. The virial equation has the most sound ____ foundation and can achieve desirable accuracy
expansion, inverse, theoretical
The interface between the system and the surroundings
boundary
Can exchange both energy and matter with its surroundings
open system
Can exchange energy but not matter with its surroundings
closed system
can exchanged neither energy nor matter with its surroundings
isolated system
a physical property that depends only on the present state of the system and is independent of how the state was prepared and the past history of the system
state function
some examples of state functions
density, internal energy, pressure, volume, temperature
