Why does soda fizz when you put salt in it?

Question

I think it has something to do with a chemical reaction

Answer 1

There is actually no chemical reaction going on. What you're seeing is dissolved carbon dioxide released from solution; water (which is mostly what soda is) can dissolve only so many things, and as one species is added to solution and dissolves, another will either precipitate out or, in CO2's case, effervesce from solution.

This is a physical change, not a chemical reaction.

Answer 2

Carbon dioxide (the bubbles in the soda) is very poorly soluble in water. The oxygen atoms are double-bonded to the carbon atom, so the hydrogen bonds they form are extremely weak. But salt is very soluble - it ionizes completely in water, forcing the carbon dioxide out of solution. This is known as "crashing", and it is a widely used technique in organic chemistry to seperate a reaction product that is not completely insoluble in the reaction mixture. Peace!