I'd like to qualify my model. I've been modeling my gas as an ideal gas, so that there are no interactions between particles except possibly perfectly elastic collisions.
I mention this because if there were for example attractive van der Waal interactions between the gas molecules, a) an increase in the average inter-particle distance as would happen in an expansion ' b) might lead to an increase in potential energy (since increasing distance in attractive interactions increases potential energy), c) which would come at the expense of kinetic energy (since we're assuming energy is conserved in free expansion), d) which for an ideal gas would result in a decrease in temperature (since for an ideal gas, temperature is proportional to average kinetic energy).
I had not considered that Lane's statement that this was a CO2 cartridge might be important to his model - I simplified to the ideal gas model and that might have thrown away important features.
I'd like to qualify my model. I've been modeling my gas as an ideal gas, so that there are no interactions between particles except possibly perfectly elastic collisions.
ReplyDeleteI mention this because if there were for example attractive van der Waal interactions between the gas molecules,
a) an increase in the average inter-particle distance as would happen in an expansion '
b) might lead to an increase in potential energy (since increasing distance in attractive interactions increases potential energy),
c) which would come at the expense of kinetic energy (since we're assuming energy is conserved in free expansion),
d) which for an ideal gas would result in a decrease in temperature (since for an ideal gas, temperature is proportional to average kinetic energy).
I had not considered that Lane's statement that this was a CO2 cartridge might be important to his model - I simplified to the ideal gas model and that might have thrown away important features.