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### 8.101 (c) and (f)

Posted: Sat Feb 10, 2018 3:47 pm
A technician carries out the reaction 2SO2 (g) + O2 (g) --> 2SO3 (g) at 25 degrees celsius and 1.00 atm in a constant-pressure cylinder fitted with a piston. Initially, 0.030 mol SO2 and 0.030 mol O2 are present in the cylinder. The technician then adds a catalyst to initiate the reaction.

(c) Assuming that the reaction goes to completion and that the temperature and pressure of the reaction remain constant, what is the final volume of the cylinder?

(f) Calculate the change in internal energy for the reaction.

This is more of a concept question, but I thought that when temperature of the reaction remains constant, then the internal energy also remains constant, so change in internal energy would be 0?

### Re: 8.101 (c) and (f)

Posted: Sat Feb 10, 2018 4:02 pm
From my understanding, internal energy is found by the work and heat of a system so even if temperature is constant, the internal energy can change with the amount of work done.

### Re: 8.101 (c) and (f)

Posted: Sat Feb 10, 2018 4:55 pm
Hey,
A change in temperature is associated with the amount of heat energy transferred or absorbed. So even if temperature is constant, work energy can be done, and this would be the change in internal energy.

### Re: 8.101 (c) and (f)

Posted: Sat Feb 10, 2018 5:41 pm
I think because the problem doesnt say that the chemical reaction is isothermal, then delta U will not be equal to 0. THat is why part e asks you to calculate the enthalpy.