作者airers (air)
看板Chemistry
標題Re: [學科]幾題物化問題 麻煩大大
時間Mon Jul 23 14:46:25 2012
※ 引述《ppppp367 (小p)》之銘言:
: 1.A gas at 250k and 15 bar has a molar volume 12 per cent
: larger than that calculated from the perfect
: gas law calculate (a) the compression factor under these conditions and
: (b) the molar volume of the gas
15bar = 15/1.01325 atm = 14.8 atm
n = 1
PV = nRT (for ideal gas)
14.8 * V = 1 * 0.082 * 250 ==> V = 1.385 L
real gas => 1.385 * 1.12 = 1.55 L (for part b)
PV = jnRT
14.8 * 1.55 = j * 1 * 0.082 * 250 ===> j = 1.12 (for part a)
: 2.I2 has a heat capacity Cp of 80j/mol k and a boiling point at 458k
: When 1 mol of I2 358k to 458k in the liquid state at 1atm, calculate the
: (a)三角形h (b)三角形s
H S
(a) (b) set Cp independent of T (liquid state)
(a) △H = n Cp dT = 1 * 80 * ( 458 - 358 ) = 8000 J
(b) △S = (Cp / T) dT = 80 ln (458/358) = ...
: an electric current of 2.0A from a 12V supply is passed
: for 1 hour through a resistance the liquid vaporized completely at 458k
: and 1 atm calculate(c) Q(d) W (e)三角形U (f)三角形H (g)三角形S
Q由電提供 我不會XD
Q得到後 Qp = △H 再帶入 △G = 0 = △H - T△S 得S
.....不太會XD
: the vapor at 458K and 1 atm was then heated to 558K and 2 atm
: calculate (h)三角形U (i)三角形H (j)三角形S
: (for the I2 vapor Cp=30+0.005T J/(mol K)
: 麻煩大大幫忙 這兩題真想很久還是卡關
: 大大解出來 一定P幣奉上 感謝
(h) (i) (j) 458k 1atm --> 558k 2atm
這邊就不是很確定了..
△H = n Cp dT = (30+0.005T)dT 由458積分到558
△U = n Cv dT = n (Cp - R) dT 同上
△S = (30+0.005T)/T dT 458積分到558 ...........以上沒考慮壓力的影響
不確定可不可以
很久沒碰了 不知道有沒有錯 有錯請指正
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※ 編輯: airers 來自: 140.114.44.228 (07/23 18:58)