[化學] 熱力學 W

作者: asd789456123 (123)   2014-12-01 11:37:34
1.30度C定溫下,一理想氣體由最初壓力2.50atm及體積3.00L
膨脹至最終壓力1.50atm及體積5.00L,試計算氣體所做最大功.
Ans:-0.388J
這一題我的算法是W=-PΔV=-1.5*2*101.32=303.96J,請問是不是答案問題?
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2.A sample of an ideal gas is expanded reversibly at a constant temperature of
25度C from an initial pressure of 4.00atm and a volume of 250.0ml to a final
pressure of 1.00atm. Caculate W.
Ans:W=-140J
這題好像是等溫可逆膨脹,所以我用W=-nRTIn(V2/V1)但題目沒給n?
所以我用W=-PΔV=-1*(4.0.25/1-0.25)=-0.75*101.32=75.99J
感謝各位看完我的問題,還請各位賜教
作者: stevennian (stevennian)   2014-12-11 12:12:00
有PVT可以求n,第一題外壓沒有固定,應該用你第二題寫的算式做
作者: asd789456123 (123)   2014-12-18 22:29:00
感謝樓上

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