A Química do Sal


Uploaded by quimicadascoisas on 12.03.2012

Transcript:
THE CHEMISTRY OF THINGS
When we think of chemicals that contribute to our welfare,
we rarely think of sodium chloride
... the ordinary "kitchen salt".
Today we talk about it in the Chemistry of Things.
Salt is one of the chemical compounds in longest use by Man
for its ability to preserve food,
which turned it into highly valued merchandise.
Food preservation by salt is in fact one of the foundations of our civilization
as Man was freed from a seasonal dependence on food
and could store food reserves for winter during the summer.
Adding salt to food triggers a process of osmosis
which causes water to flow from an environment with a low salt concentration
to one with a higher concentration.
In this way, salt removes water from food,
inhibiting the growth of micro-organisms.
These micro-organisms that cause food to rot and produce toxins that affect our health
do not survive under a high osmotic pressure,
i.e., where water is taken from them by osmosis.
Sodium chloride is also a dietary component essential to the functioning of our body.
The dissolution of "salt" originates sodium and chloride ions
which are present in all tissues and fluids of the human body,
where they play very diverse roles.
For example: they are essential for maintaining the healthy osmotic balance
between the cellular and extracellular fluids;
they ensure the balance between positive and negative ions in the body
and have an important role in the nerve impulse transmission throughout the body.
But in excess, salt can cause health problems.
Do not exceed the daily intake of 6g recommended by the World Health Organization
if you want to benefit from the chemistry of salt!
To know more about the chemistry of salt
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