How does a salt solution may be used as a weed killer?

Question

plz answer my question with the idea that plasmolysis is due to the loss of water from a cell.

Answer 1

The main mechanism that cells use to draw water in is osmosis. Water is usually fairly pure when it falls out of the sky and cells are heavily saturated with all kinds of stuff, so the water just naturally is sucked inside cells... sometimes so strongly that this can threaten cells (which is why cell walls are so handy for plants).

If the only water available, however, is a very saturated solution already (like salt water might be) then you can have the opposite problem. Instead of water going into cells, it will naturally be sucked out. And having too little water is no more healthy than having too much.

Because most land creatures do not come into contact with that kind of environment much, they usually have no defense against it. This is why a sailor stranded on the ocean dies from drinking sea water and it is also why you can use salt water as a weed killer. It's not too popular in the latter purpose, though, because it will just as easily kill your grass and any other plants around. Conquering armies interested in vengeance would sometimes 'salt the land' and prevent any crops from growing there until all the salt had been leached out of the soil... a process that might take years and years. But that's probably more than a little off topic.

Peace.