Saline basically means slat water, though the type of sodium vaires from place to place and the water usually has a mixture of different salts.
The average salinity (saltiness) of world ocean water is 35 parts per thousand.
Parts per thousand is just a way of measuring concentration, it is more of a ratio that an actual mesaurement. The idea is that it is always proportional no matter what the measurement scale is, e.g. if you have a kilogram of saline water with 1 part per thousand salt then you would have one gram of dissolved salt in the water.
This means that if you have a kilogram of average saline ocean water then it would have 35 grams of salt in it. Equally if you have a metric ton of water then it has 35 kilograms of disolved salt in it.
Anyway, 35 ppt (parts per thousand) is the average salinity, but almost all sea/ocean water is in the small scale between 30 and 38ppt salinity.
The most common majority of sodium in the waters composition is sodium chloride but other salts appear as well. The full elemental composition of a 35 ppt saline solution is this:
Element | % |
Oxygen | 85.84 |
Hydrogen | 10.82 |
Chloride | 1.94 |
Sodium | 1.08 |
Magnesium | 0.1292 |
0.091 | |
Calcium | 0.04 |
Potassium | 0.04 |
Bromine | 0.0067 |
Carbon | 0.0028 |
You can see that the two main elements in the the table are oxgyen (making up over 4/5 of the solution) and hydrogen which are the two elements commonly used to express water as an equation.
Together they make up 96.66% of the water, leaving only 3.34% to be made up of the other elements.
This shows how little salt there really is in the saline water and what a difference it can make to compeletely change the environment from fresh to salt water and change everything about the waters use and what can live in it.
I have made a couple of pie charts to show how these figures looks visually:
The Chloride and Sodium go together to create the salt Sodium Chloride and make up 3.02% which is the majority of what is left.
The other elements are tiny molecules of metals, non-metals and halogens and are insignificant in comparison to the other elements as there is so little of each. Together these remaining elements make up only 0.32% of the 35ppt saline solution.
Just because there is so little of each of these elements doesnt actually mean that they are useless, as they are some of the most important elements in creating life, especially calcium and carbon which I know all lifeforms are based around.
I wouldn't know exactly as it is quite complicated and probably a bit beyond my understanding but I would say that it isn't a coincidence that life is so abundant in the seas and oceans with these remaining elements present and completely surrounding everything that lives in them
(e.g. we obviously have these elements on land as well but we are not constantly swimming through them or breathing them in)
DENSITY
Interestingly saline water has a higher density than fresh water because the sodium chloride increases its mass. This doesn't afect water much physicaly although it means that salt water is heavier than fresh water and creates more pressure at greater depths.
It also means that energy has different effects on the water.
There is such a thing as heat energy but there is no such thing as cold energy because it is not physical but is a side effect of a lack of heat.
Heat also cannot pass from a colder body to a hotter, it always goes the other way.
The salt in saline water acts as a metaphorical insulation and changes how heat energy affects the substance.
The boiling point of water is 100 degrees C and the freezing point is 0, but salt increases the boiling point and decreases the freezing point depending on how much salt there is. For approximately every 30grams of salt added and dissolved into water, the boiling point will rise about half a degree C.
The salt in the water effectively stops the heat and lack of heat from affecting the water molecules at the regular temperatures.
In fact the freezing point of water can go down dramatically, as I found that the lowest recorded freezing point of water was around the antarctic and was about -2.8 degrees C (bearing in mind that this is still flowing water and not ice).
Although this might not seem that interesting to most people, it does to me.
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