作者vicboyso (Vic)
看板TransBioChem
標題[問題] 大雜燴 問題 集中發問
時間Wed Jul 7 01:29:15 2010
1) The freezing point of 4.6 g of formic acid (HCOOH) dissolved in 1.0 kg of
benzene (C6H6) is depressed by 0.26 oC, whereas that for the same amount of
HCOOH dissolved in 1.0 kg of water is lowered by 0.19oC. (Kf , C6H6 = 5.12 oC
kg/mol; Kf H2O = 1.86 oC kg/mol) In order to explain these observations, one
need to assume that HCOOH is
A) associated in C6H6 in monomeric in water.
B) monomeric in C6H6 and associated in water.
C) associated in C6H6 and dissociated in water.
D) dissoiciated in C6H6 and monomeric in water.
E) monomeric in C6H6 and dissociated in water.
F) none of the above
看不太懂 題目的意思 可以請問 再問甚麼嘛
2) Balance the reaction below in acidic solution.
IO3- + I- -> I2
What volume of 0.352 M HCl is needed to produce 2.48 x 10-3 moles of iodine,
I2, with an excess of KIO3 and KI?
(a) 2.48 mL (b) 4.96 mL (c) 7.05 mL (d) 14.1 mL (e) none of these
以下是我的算試
6HCl + KIO3 + 5KI -> 3I2 + 3H2O + 6KCl
V X 0.352 = 2.48X10 負3
算出來的V 要X2嗎?
還是我想錯了
感謝
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 111.248.5.141
1F：推 nodal:associated=變少 monomeric=不變 dissoiciated=變多 看i值 07/07 01:32
2F：→ nodal:i>1就是變多 i=1就是不變 i<1就是變少 07/07 01:33
3F：推 nodal:不是0.352*V 是0.352/2V = 2.48*10^-3 07/07 01:36
4F：推 nodal:是乘沒錯 我看錯單位了 > < 07/07 01:45