3 ms·
Probably a naive question, but why is it the case? we have the basic formula of thermodynamic: PV = nRT, with n and R being constant, so if I keep the volume th
by S4M 11y ago
Probably a naive question, but why is it the case? we have the basic formula of thermodynamic: PV = nRT, with n and R being constant, so if I keep the volume the constant and decrease the temperature, it would decrease the pressure P, making the material less hard. What am I missing?
- pm90 11y agoPV = nRT is for ideal _gases_, ice is solid.
- jheriko 11y agophase transitions are complicated. when something is a gas that rule applies because the forces between the constituent particles are neglible except for the electromagnetic interaction causing scattering (i.e. particles bouncing off each other, or the surroundings). this is the pressure from that formula. increasing temperature increases the energy in the system, resulting in more collisions, and more pressure. decreasing it results in less as you correctly point out. in a solid the electromagnetic interaction is constantly present and locks the constiuent particles nearly in place, so that when excited they 'vibrate' around their location, rather than moving freely like in a gas. this has different consequences, so that decreasing the temperature will increase the rigidity of the material since the particles will become ever less likely to achieve the energy required to escape their electromagnetic 'traps'.