Sea Water Ice Density

the temperature to freeze the seawater will be lower also.

You hit the ice in fine form, GA. The question reminds me of a time I was putting ice in a scotch only to find out that now my scotch was salty, ptuh. In this case the water was from a well and tasted fresh. Later found out the well water had a slightly elevated conductivity of about 1800 μS/cm. Enough that the outer shell of the ice cubes were "salty" as was the tray residual after the ice cube was removed. I tell this story so you won't ruin another scotch, damn shame.

Stick some sea water in the freezer. When it does freeze, will the center be fresher than the surface or should that be the other way around? It may be an interesting way to desalination. Calls for an experiment but I don't live near the ocean.

Why would you ruin good scotch by putting ice in it?

Thank you for your reply. I have another question, what might be the highest density value for sea water ice. Is there any sea water ice having density more than 1 g/cm3?

Please read my previous answer again. There is no single number that accurately describes the density of sea ice. You can, however, take a specimen of sea ice and measure its average density. I am unable to say whether any possible sea ice might have an average density greater than 1 g·cm^-3, and I doubt anyone could say that with 100% confidence, but I have little doubt that any sea ice you might actually find in nature is somewhat below1 g·cm^-3.

Why not do some experiments? Make up salt water solutions and freeze them. Then drop them in fresh water and see if they sink or float.

Yes, see Wiki .

Although sea water ice can have densities greater than 1 gm/cm3, so does salty sea water ( with a density around 1.03 gm/cm3) and it allows the sea ice to float. Otherwise our oceans would freeze from the bottom up. The predicting of the density of sea ice is difficult to say the least but I still think its density will be less than the water below if measured as an average.

If seawater is frozen the ice is fresh. Icebergs are fresh and there have been suggestions to tow them from Antarctica to Australia to provide fresh water. Ice is less dense than water so floats in fresh water (well known fact). It floats a little higher in seawater as the water density is higher.

Typical seawater contains about 2.7% w/w sodium chloride, with other salts giving total about 3.5%. Varies with latitude, gets stronger going from poles to Equator. Behaviour of solution of sodium chloride on freezing is :-

If the solution is < 23%, pure ice separates out and the solution gets stronger. This continues until concentration 23% is reached, when the solution as a whole freezes, at -23°C.

If the solution is > 23%, pure salt separates out and the solution gets weaker. This continues until concentration 23% is reached, when the solution as a whole freezes, again at -23°C. This temperature -23°C is the eutectic point.

Solubility of sodium chloride at 0°C is 35.6% w/w, and doesn't vary much with temperature, 39.8% at 100°C.

Cheers........Codey