Hello all, I have following questions dangling in my mind, with a positive attitude of seeking help i want put them infront you geneus people, in my earlier post i get a good result and now i want to more insight of the very matter. kindly help me. Using the concept of state of system, i understand that the state represent the condition of the system which it has. Further some set minimum values of state functions are required to specify the full discription abouy the system. Am I right? I now want to know following for crystal clear understanding. THE FOLLOWING IS TRUE FOR ALL IDEAL GASES. We know two similar systems having same volume, may have different temperature, and(PV= nRT) two similar systems having same pressure, may have different temperature, 1.CAN TWO SIMILLAR SYSTEMS HAVING SAME INTERNAL ENERGY, MAY HAVE DIFFERENT TEMPERATURE? 2.IS IT POSSIBLE FOR TWO SIMILAR SYSTEMS AT SAME STATE ( THEY SURELY WERE AT SAME TEMPERATURE, ISN'T) TO HAVE DIFFERENT INTERNAL ENERGY? 3.IS IT POSSIBLE FOE ANY PROCESS (TO OCCUR) WHERE THE INITIAL AND FINAL STATES ARE DIFFERENT THOUGH THE CHANGE IN INTERNAL INERGY IS ZERO? I expect the answer of last question in affermative just as two at two different states a system may have same temperature it may also have same internal energy, well i want response dor all my questions so that things may get fully clearified, THANKS A BUNCH:) AND REGARDS!!