作者vicboyso (Vic)
看板TransBioChem
标题[问题] 大杂烩 问题 集中发问
时间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 题目的意思 可以请问 再问甚麽嘛
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
以下是我的算试
6HCl + KIO3 + 5KI -> 3I2 + 3H2O + 6KCl
V X 0.352 = 2.48X10 负3
算出来的V 要X2吗?
还是我想错了
感谢
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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 111.248.5.141
1F：推 nodal:associated=变少 monomeric=不变 dissoiciated=变多 看i值 07/07 01:32
2F：→ nodal:i>1就是变多 i=1就是不变 i<1就是变少 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:是乘没错 我看错单位了 > < 07/07 01:45