作者Epondo (Epondo)
看板Chemistry
标题[学科] M与m的转换
时间Tue Jun 29 12:08:23 2010
Fish blood han an osmotic pressure equals to that of seawater
If seawater freeze at -25 C,what is the osmotic pressure of
the fish blood at 25 C
Kf=1.86 for water : the density of seawater is 1.2g/ml
and assume that the dissolved substance in seawater is NaCl(58.5)
解答:
Tf=iKfm
2.5=1.86*m*2 => m=0.672
换算成 CM=0.667M => 渗透压=iCMRT
=2*0.776*0.082*298=37.9atm
为什麽CM是0.667? 我自己是把 0.672m=0.672mole/1kg溶剂
然後1kg溶剂 => D=M/V 所以V=0.83公升 所以CM=0.667/0.83=0.804
感谢各为解答~
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1F：推 Falajack:密度里的M是整个溶液重，不是只有溶剂 07/02 08:53
2F：推 pingshung:CM=(溶质莫尔数)/(溶液体积) 07/03 02:12