化学问题

look416

我想问一下，在我的F4的课本里面，盐的定义是an ionic compound that is formed when the hydrogen ion in an acid is replaced by a metal ion or and ammonium ion.
可是在我的F5 BIo课本里面的第一课，plasma consists of salts...
a：sodium ion,potassium ion, and chloride ion
b: Calcium ion

可是如果将讲的话，plasma不就是没有含有hydrogen。
再说，salts is compound 这种说法，如果是真的，那么sodium ion，potassium ion这些都不能被称之为salts了咯
酱是书本写错呢，还是我理解错呢？

chan1314

原帖由 look416 于 29-12-2007 12:26 AM 发表
我想问一下，在我的F4的课本里面，盐的定义是an ionic compound that is formed when the hydrogen ion in an acid is replaced by a metal ion or and ammonium ion.
可是在我的F5 BIo课本里面的第一课，plasma co ...

比如说 HCl , 是 acid.
把 H 换乘 sodium = NaCl << 盐。
一个巴掌拍不响， 切忌切忌

morphv02c01

The definition can be accepted.. for exmp, NaCl, NH4Cl etc..
But, this is the fact, in aqueous solution, the salt will not exists and a compound, it will exist as individual ions, if the solution is not saturated.
Individual ions like K+, Na+ are not salts, they are ions, they are not compound either.

I suppose the plasma you mentioned is blood plasma, there will be presence of salts, but  the explanation might be gross. I think it is trying to say that there are the presence of salts like NaCl etc in the plasma, but they exists as seperate individual ions, serving as electrolytes. Sodium ion, potassium ion are important for h=the generation of nerve impulse(action potential), calcium ions on the other hand are responsible for the fusion of vessicle containing neurotransmitter to the presynaptic membrane. Cl ions are, involve in respiration, were chloride shift occurs when erythrocytes perform it's responsibilitity as oxygen carrier(main).

wenyu0705

原来如此~~~~~~~

wenyu0705

可是H和Na不是都一样只有charge +1吗？

jiko

原帖由 wenyu0705 于 27-1-2008 02:46 PM 发表
可是H和Na不是都一样只有charge +1吗？

是+1。。。
但是他们是不一样的compound来的
NaCl --->ionic compound
HCl--->covalent compound