Interactions Na and Cl and forming NaCl

[MiZuboov]

Hi!
There are in planted tanks different fertilisers with chlorides, but we have from tap water some sodium. Are they mixing on the NaCl? Can we get salinity in freshwater tank that way?
ICP test show us Sodium and Chlorides concentrations in aquarium, but why they doesn’t mixing on NaCl? I mean.. we have freely Na molecules and Cl molecules?
Hi!
There are in planted tanks different fertilisers with chlorides, but we have from tap water some sodium. Are they mixing each other into the NaCl? Can we get salinity in freshwater tank that way?
ICP test show us Sodium and Chlorides concentrations in aquarium, but why they doesn’t mixing each other into the NaCl? I mean.. we have freely Na molecules and Cl molecules? Or ICP reveals us Na and Chlorides that are form Salinity?

 

[Randy Holmes-Farley Verified Community Expert]

Sodium ions and chloride ions are both present in seawater and nearly every natural freshwater sample. They are unattached to each other when dissolved, and move independently.

All of the ions in seawater, including, but not limited to, sodium and chloride contribute to salinity to some extent. Magnesium and sulfate are the next most significant contributors.

I’m not sure if that answered your question or not.

 

[MiZuboov]

Sodium ions and chloride ions are both present in seawater and nearly every natural freshwater sample. They are unattached to each other when dissolved, and move independently.

All of the ions in seawater, including, but not limited to, sodium and chloride contribute to salinity to some extent. Magnesium and sulfate are the next most significant contributors.

I’m not sure if that answered your question or not.

When we add the balling, we get an increase in salinity. How likely is it, according to the same principle, to get an increase in salinity in a fresh aquarium due to the add of fertilizers with chlorides, provided that there is sodium in the water?

 

[Randy Holmes-Farley Verified Community Expert]

When we add the balling, we get an increase in salinity. How likely is it, according to the same principle, to get an increase in salinity in a fresh aquarium due to the add of fertilizers with chlorides, provided that there is sodium in the water?

The increase is small from fertilizers. We add a huge amount of sodium carbonate and calcium chloride relative to fertilizers in either system.

 

[MiZuboov]

The increase is small from fertilizers. We add a huge amount of sodium carbonate and calcium chloride relative to fertilizers in either system.

Why do free sodium and chlorine molecules not always bind to sodium chloride?

 

[IceNein]

Why do free sodium and chlorine molecules not always bind to sodium chloride?

That's the nature of ions. They are weakly bound. They do not have covalent bonds, so when they are in a bipolar solution like H2O, they disassociate and move about the solution independently.

 

[Randy Holmes-Farley Verified Community Expert]

Right. Only if you try to dissolve more sodium and chloride than the solubility limit in water (which is high) will any attached NaCl form and make a solid.

 

[MiZuboov]

I guess I'll have to start over. What is salinity? I used to think they were NaCl molecules. Or is salinity the presence of sodium and chloride ions in the water?

 

[MiZuboov]

Let's say I have 150 mg/l of sodium in my water. How much calcium chloride should be added to raise the salinity by 1 degree?

 

[Randy Holmes-Farley Verified Community Expert]

Salinity has a number of definitions, mostly designed to facilitate easy measurement, but in its primary form it is the weight of everything in the water that is not water.

That includes sodium and calcium and uranium and chloride and sulfate and vanadium and dozens more. There are a few things it may not include, such as O2 and N2 and helium, but that’s a very minor detail.

Salinity is not measured in degrees that I know of.

The salinity of average worldwide seawater is 35 ppt, which means 35 grams of ions in 1 kg of total seawater.

No matter what else is already in the water, 1 gram of anhydrous calcium chloride will raise the salinity of 1 kg of seawater by 1 ppt.

 

[MiZuboov]

It turns out that under normal conditions, NaCl does not exist in water? Are there only sodium and chloride ions?

Salinity has a number of definitions, mostly designed to facilitate easy measurement, but in its primary form it is the weight of everything in the water that is not water.

That includes sodium and calcium and uranium and chloride and sulfate and vanadium and dozens more. There are a few things it may not include, such as O2 and N2 and helium, but that’s a very minor detail.

Salinity is not measured in degrees that I know of.

The salinity of average worldwide seawater is 35 ppt, which means 35 grams of ions in 1 kg of total seawater.

No matter what else is already in the water, 1 gram of anhydrous calcium chloride will raise the salinity of 1 kg of seawater by 1 ppt.

 

[Randy Holmes-Farley Verified Community Expert]

It turns out that under normal conditions, NaCl does not exist in water? Are there only sodium and chloride ions?

Correct, only sodium ions and chloride ions.

 

[MiZuboov]

The salinity of average worldwide seawater is 35 ppt, which means 35 grams of ions in 1 kg of total seawater.

No matter what else is already in the water, 1 gram of anhydrous calcium chloride will raise the salinity of 1 kg of seawater by 1 ppt.

Ppt? Is not ppm?

 

[gbroadbridge]

I'm finding this thread quite educational :)

 

[KStatefan]

Ppt? Is not ppm?

ppt (part per thousand)
ppm (part per million)

 

[Randy Holmes-Farley Verified Community Expert]

Ppt? Is not ppm?

As I mentioned, seawater salinity can be given in many different units of measure.

35 ppt = 35,000 ppm = 35 g/kg ~ 35.8 g/L

 

[MiZuboov]

Thank you all a lot!

 

[MiZuboov]

ppt (part per thousand)
ppm (part per million)

I thought “t” is trillions

 

[Randy Holmes-Farley Verified Community Expert]

I thought “t” is trillions

It can be, but for salinity ppt is part per thousand.