Kosher salt is sodium chloride.
Yes
All salt is kosher. "Kosher salt" is a particular grade of salt, with coarse crystals, that is used for making meat kosher, and is also useful in cooking. It's no more kosher than any other kind of salt.
Almost all salt is kosher by default. The only issue would be if non-kosher additives such as flavourings were added to the salt. Sea salt is healthier than traditional table salt as the sodium level in sea salt is far lower.
No. Quick salt is another name for saltpeter, or potassium nitrate: among other things, it's used for making cured meats like salami. Kosher salt is made of sodium chloride like regular table salt, but has larger grains and is used to draw blood out of meat in order to make the meat kosher (hence the name).
Yes. The substance itself is intrinsically kosher. The only question might arise if the sea salt is processed or packaged on machinery, or in a facility, where it could come in contact with non-kosher ingredients of other products.
Most salt is kosher by default unless additives such as flavourings are added, at that point the salt would have to be certified kosher. 'Kosher salt' refers to a large grain salt that is used during the process of kashering meat. Iodized salt is kosher.
Regular table salt.
No, it is not. Almost all mass produced salts are considered kosher and have been certified kosher by a rabbi or authorized organization. Kosher salt gets its name from from what it was originally used for. Kosher salt is much larger grains and was used to pull the blood out of meats so that it meets the Jewish guidelines. That process is often referred to as "koshering" and that's where kosher salt got its name from. But any salt that is certified free of additives can be certified kosher and used.
Cabbage and vinegar, or cabbage and salt.
All salt is kosher unless something is added to it to render it not kosher. If the question is in regard to kashering salt, the salt used to kasher meat, that product is not suitable for cooking as it is an extra coarse salt that does not dissolve well.
Sea salt comes from evaporated seawater. The mineral content of sea salt is not limited to the sodium and chloride that make up the traditional salt molecule. Additional minerals can give the salt subtle flavor characteristics that can enhance foods. But, Kosher salt is pure sodium chloride, usually without any additives, and it often comes in coarse crystals. It is not necessarily a kosher product, but it can be certified as kosher for Passover use. The real connection is that kosher salt has been used in the process by which foods are made kosher. It is no better or worse than any other form of table salt. __________ Almost all salt is kosher by default unless flavourings are added to it. Traditionally, kosher salt referred to a coarse salt that is used during the process of kashering meat.