- #1

- 1

- 0

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter shawn100
- Start date

- #1

- 1

- 0

- #2

Andrew Mason

Science Advisor

Homework Helper

- 7,694

- 403

Use PV=nRT.shawn100 said:

If T is constant then [itex]P_iV_i = P_fV_f[/itex]. So you can work out what the final volume is.

The work is:

[tex]W = \int_{P_i}^{P_f} PdV = \int_{V_i}^{V_f} \frac{nRT}{V}dV [/tex]

You have to work out that integral (hint: [itex]\frac{d}{dV}ln V = 1/V[/itex]) and plug in the initial and final volumes.

You don't have to do any conversions. You just need the pressure ratio P_f/P_i.

AM

[edit: this last comment is not quite correct. You do have to work out nRT = P_iV_i which means you have to do a conversion. PSIA is absolute pressure in pounds/in^2, which means you have to include atmospheric pressure. PSIG is gauge pressure, which is 1 atm less than actual. It is easier to work in MKS. I would convert to MKS and then convert back.]

AM

Last edited:

Share: