[學科] 自由能 Gibbs Energy

看板Chemistry作者 (天影)時間15年前 (2009/05/23 02:11), 編輯推噓2(206)
留言8則, 4人參與, 最新討論串1/1
Liquid sodium, Na(l), may be used as a coolant in future nuclear power plants. (a) How much heat is required to melt 100. kg Na at 1 atm, starting from 298K? (b) What are the entropy and free-energy changes accompanying the heating process? Assume the heat capacities are temperature independent. Cp = 6.7 cal/K mol (定壓莫耳熱容量) Tf = 370.9 K ΔH(fus) = 0.62 kcal/mol (熔化熱) I've already figured out the heat and entropy. But I don't know how to calculate the free energy... Seek for someone to help me.. -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 123.192.91.118

05/23 09:56, , 1F
ΔG=ΔH-TΔS 帶進去算不就好了
05/23 09:56, 1F

05/23 11:26, , 2F
是錯的呢... 跟正解(只有簡答)算出來不一樣
05/23 11:26, 2F

05/23 15:23, , 3F
a小題是要你算在298K下的溶化熱 你利用已知370.9K的ΔH
05/23 15:23, 3F

05/23 15:24, , 4F
做HEAT PROCESS圖 就可求解
05/23 15:24, 4F

05/23 16:51, , 5F
嗯,我只剩下Free energy沒算出來啊...
05/23 16:51, 5F

05/23 23:28, , 6F
Free Evergy求到熔化溫度就可以了
05/23 23:28, 6F

05/24 13:34, , 7F
嗯,熔化在熔點下是共存狀態,可是我算出來還是不一樣啊XD
05/24 13:34, 7F

05/24 13:35, , 8F
或許該提供個課本的簡答?課本是給-4.12 Mcal
05/24 13:35, 8F
文章代碼(AID): #1A5kgs-L (Chemistry)