Question

#2 An ideal gas with a fixed number of molecules undergoes the three processes described below. For each, fill in the table giving whether each quantity or change in that quantity is positive (+), negative (-), or zero (0). You must explain how you determined your answer for full points. Process #1: The gas emits heat during an isochoric process. Process #2: The gas has an adiabatic process in which its temperature increases. Q WAT AV Ap Process #3: The gas ab- sorbs heat but does a larger amount of work Q Was AT AV Ap Q WAT AV Ap (6.) Use the information from the tables to sketch each process's pV diagram. Start each process from the same point labeled i in the diagram. You don't have enough information to exactly determine the final state, but you should be able to determ- ine a possible final state. Use the isothermal graph provided as a guide to find the final state. р Isothermal V

Answer 1

2 Process -1 → The Gas emits heat during process, an isochoric P. Wgas ДТ AP ave -ve Zero o -ve nics. Heat is rejected from the Gus, usually heat rejection is assigned -ve sign in thermodynamic * As the process is isochovic i.e change in vol is ze so As heat ii rejected, temperature of Gas will fall, so Final - Tinitial *) Displacement work (dw) - P. du so Tv=0 - -ve VT-ve as v v =0, so dw=o CR Waas from Gas eqr PV = nRT NR = constant constant va

- SO, P & I as T is decreasing in this process, Press' will also decrease AP=-ve Process- The Gas has an adiabatic process in which its temperature increases. *) On adiabatic process, heal interachan a between systemet roundi is zero. so o=0 +) As temperahuse in Czeases during the process VTE tve *) Increase in temps without heat interation is only possible when process is compressive. ousing compression pressure is cséase up = tve and volume decreases the process is compressive, it means work i done on Woas Waar AP c.eur- ove *) As the system. Hence --ve ДТ AV zero-ve tve -ve tve Process 3 *) The Gas absorts heat but does a larges amount of work , of a Gas absorbs heat but does a larger amount of work, it is possible only when it uses its internal energy. Internal energy of Gas will But Internal energy is funchan tempr. gt means Temps will decrease. Decreas of

& Gas ie VT = -vel *) work is done by Gas = tue absorbs heat, ie heat is added to the system (a = tve] *) work will be positive only increases. ie expansion takes place. when vol. so tvrtve +) During expansion pressure of Gas deceases i.e vp = -ve W ДТ OV TP tve tve -ve tve ve