Why would we die if we were stranded and all we could drink was seawater (salt water)?

Question

I know it has to do with Osmosis but i don't really know what the salt will do to our insides, and i don't really know much about osmosis other than it makes things smaller.

Answer 1

Well, salt makes you thirsty. And the only reason to drink salt water is if you were stranded and thirsty. You would pretty much kill yourself drinking salt water just because the salt would dehydrate your whole body and you wouldn't stop drinking it.

Answer 2

osmosis (you learn about this in yr 11 and 12)is the passive (no energy) movement of water from a dilute solution (lots of it) to a concentrated solution (not much of it). When u are thirsty u crave water. Messages are sent to ur brain to find it. These messages are becasue the internal salt balance is not right. There is too much salt in the body and not enough water. With excess salt moving into ur body, the water that is left in your body will move out of your cells (due to osmosis). With no water in the cells, they can no longer function normally. Then you die as the cells cant work to keep u alive.

i hope that helps u

Answer 3

Osmosis is absorption through the skin.  Not making things smaller.

Answer 4

Your kidneys would be unable to process the excess salt and your organs would begin to shut down.

Answer 5

to answer you in simple form salt/sodium dehydrates you..if you drank sea water youre actually losing fluids from your body..basically die from dehydration..

Answer 6

Yes, the salt content speeds up the process of dehydration. You would be better of not drinkin anything at all if all you have is saltwater

Answer 7

All of the answers so far are correct but they really don't tell you why drinking saltwater will kill you. They correctly say that it will dehydrate you but why does it dehydrate you?

It does have to do with osmosis and diffusion. First let me explain those two terms. Diffusion is the slow movement of molecules from an area of high concentration to an area of low concentration. The easiest way to picture this is to think about dropping a drop of food coloring into a glass of water. The dye in the food coloring will eventually spread out evenly throughout the glass making the entire glass of water the same color even if you do not stir it up. The process of the dye molecules moving from the highly concentrated area of the drop of dye to the low concentration in the clear water is diffusion. The same thing will happen with stuff you cannot see like salt in water. Note that the concentration differences also apply to the water. Clear water is more concentrated water than water with dye in it.

Osmosis is the process of diffusion across a semi-permeable barrier or membrane, such as your skin or your stomach lining. A semi-permeable membrane is one that will allow some of the molecules to pass but not all of them; usually it is the size of the molecule that controls that. Osmosis is diffusion processes and like all diffusion processes, diffusion causes movement from an area with high concentration to an area with low concentration.

So why does drinking seawater kill us? The reason is that seawater has more salt in it than does our bodies. We are actually a little bit salty too, but not so salty as seawater. Osmosis plays an important part in what happens when we drink seawater. When you drink seawater you will have water in your stomach that is much saltier than the water inside your body. Salt does not move very easily across our stomach lining because it is semi-permeable and so the salt in both places pretty much stays put but the water can move back and forth fairly easily. Because the salt cannot not move, it is the concentration of the water that is important. In our body there is more water and less salt. In our stomach there is more salt and less water. So our bodies have a higher concentration of water. Diffusion drives movement from high concentration to low concentration and so the water in our body is driven out of our body towards the lower concentration of water in the salty seawater. That means that when you drink seawater it actually sucks water out of your body. So that is why drinking seawater will kill us. Drinking seawater will cause us to die of thirst faster than if we did not drink at all.

Answer 8

If ever your in a situation that you don't have fresh water get a bowl of some sort cover w/ a plastic bag and put the water inside the bowl. weigh down the bag w/ something , a rock , keys. Leave for a day or two. the condensation will remove the salt and now you have fresh water. The salt will dehyrdrate you and mixed w/ the sun and heat you can get very sick and die faster.