Please answer! What would happen if you put ocean water on a wound/open injury and burn?

It would sting ; It would put you at risk for infection from organisms in the ocean water.
Sea water and wounds. Sea water is a Hypertonic Saline solution, not entirely different from the saline we put on open wounds. Sea water is not overly contaminated, so the great risk of doing harm is really very low. We use Hypertonic Saline to sterilize pool water, so use on wounds isn't a poor choice.