s**l
发帖数: 11983 | 1 salt: 盐。
sodium: 钠。
Technically salt can be any ionic compound formed by reacting an acid and a
base, but most of the time the word is used to refer to table salt, which
is sodium chloride or NaCl. So, you know salt contains sodium, but the two
chemicals aren't the same thing.
What Is Sodium?
Sodium is a chemical element. It is very reactive, so it isn't found free in
nature. In fact, it undergoes spontaneous combustion in water, so while
sodium is essential for human nutrition, you wouldn't want to eat pure
sodium! When you ingest salt, the sodium and the chlorine ions in sodium
chloride separate from each other, making the sodium available for your body
to use.
Sodium in the Body
Sodium is used to transmit nerve impulses and is found in every cell of your
body. The balance between sodium and other ions regulates the pressure of
cells and is related to your blood pressure, too.
How Much Sodium Is in Salt?
Because sodium levels are so critical to so many chemical reactions in your
body, the amount of sodium you eat or drink has important implications for
your health. If you are trying to regulate or limit your intake of sodium,
you need to realize the quantity of salt you eat is related to the amount of
sodium, but is not the same. This is because salt contains both sodium and
chlorine, so when salt dissociates into its ions, the mass is divided (not
equally) between sodium and chlorine ions.
The reason salt isn't just half sodium and half chlorine is because a sodium
ion and a chlorine ion don't weight the same amount.
Sample Salt and Sodium Calculation
For example, here is how to calculate the amount of sodium in 3 grams (g) or
salt. You will notice 3 grams of salt does not contain 3 grams of sodium,
nor is half the mass of salt from sodium, so 3 grams of salt does not
contain 1.5 grams of sodium:
Na: 22.99 grams/mole
Cl: 35.45 grams/mole
1 moles of NaCl = 23 + 35.5 g = 58.5 grams per mole
sodium is 23/58.5 x 100% = 39.3% of salt is sodium
Then the amount of sodium in 3 grams of salt = 39.3% x 3 = 1.179 g or about
1200 mg
An easy way to calculate the amount of sodium in salt is to realize 39.3% of
the amount of salt comes from sodium. Just multiply 0.393 times the mass of
the salt and you will have the mass of sodium. | G**5
发帖数: 394 | | l*********u
发帖数: 19053 | 3 高中以后，再没学过化学，看到NaCl，很亲切 :)
a
in
【在 s**l 的大作中提到】
: salt: 盐。
: sodium: 钠。
: Technically salt can be any ionic compound formed by reacting an acid and a
: base, but most of the time the word is used to refer to table salt, which
: is sodium chloride or NaCl. So, you know salt contains sodium, but the two
: chemicals aren't the same thing.
: What Is Sodium?
: Sodium is a chemical element. It is very reactive, so it isn't found free in
: nature. In fact, it undergoes spontaneous combustion in water, so while
: sodium is essential for human nutrition, you wouldn't want to eat pure
| s*********n
发帖数: 39 | 4 学了生物化学，感觉跟化学２码事儿。
【在 l*********u 的大作中提到】
: 高中以后，再没学过化学，看到NaCl，很亲切 :)
:
: a
: in
| l*********u
发帖数: 19053 | 5 高中学的化学，应该属于初级化学吧，生物化学大概算高级了。
最喜欢高中化学实验课，可以鼓捣氧化铜啥的，五颜六色的 :)
【在 s*********n 的大作中提到】
: 学了生物化学，感觉跟化学２码事儿。
| G**5
发帖数: 394 | 6 喜欢捣鼓。
【在 l*********u 的大作中提到】
: 高中学的化学，应该属于初级化学吧，生物化学大概算高级了。
: 最喜欢高中化学实验课，可以鼓捣氧化铜啥的，五颜六色的 :)
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