We can, by filtration or destillation. Trouble is, it takes a fair amount of energy, so usually it makes more sense to look for freshwater.
Drinking salt water leads to dehydration.
Because the water in the ocean is salt water. If you have too much salt, it can be poisonous, and with salt water it's pure salt. Also the fact that you need other foods in order to survive.
one contains salt
Because the salt in the salt water will remove more water from your body than it introduces. In other words, drinking salt water will dehydrate you.
just add salt to it
Yes, drinking water does boil at a lower temperature than salt water.
Cooling a salt solution will crystalize the salt presumably by lowering the solubility, allowing the solution to be filtered and pure water obtained. Drinking salt water will lead to dehydration.
No
Add salt
by cleansing it out
yes
salt water vaporization