Can someone briefly explain the reaction between Na and Cl and the reaction between NaCl and H2O?

Answer 1

There is *no* reaction between NaCl and H2O. It's merely a dissolution, not a reaction.

Na and Cl (actually Cl2) will react to form NaCl. It's an exothermic reaction.

Answer 2

Na and Cl are just two oppositely charged ions that attract each other through ionic interactions. When immersed in water, H2O will disrupt these ionic interactions (between Na and Cl), so now the groupings are: Na-H2O, and Cl-H2O. This makes it look like the NaCl has "dissolved" in water, but actually, water is just getting inbetween the two so they can't form a salt.

(Think about it like a referee coming between two boxers locked together).

Answer 3

Solid sodium chloride is an ionc bond forming crystal. It is held together by the positive charges of sodium cations and negative charges of chloride exerting an attractive force on one another.

Solid NaCl dissolves in water by separating the ionic bonds of the solid. The dissolved sodium cations and chloride anions are entropically favored, but enthalpically not, so the water actually gets colder (it takes up heat). This is because the randomness of having lots of individual ions in water is preferred to having them arranged in a crystal lattice of NaCl. The reaction would be written as:

NaCl (s) -> Na+ (aq) + Cl- (aq)

Answer 4

it's not a reaction. all that happens is that the ions are solvated by the water molecules. Na ionically bonds to Cl in a crystal matrix.