NaCl is dissolved in water. Why no "poof?"

Factual Questions
1

I understand that H2O acts as a solvent to break the ionic bond, and that one pole of the water molecule will face Na while the other pole will face the Cl because of the polar quality of the water molecule.

But why does Sodium have to be metallic in order to react with water? Why doesn’t plain ol’ NA+ go, “Hey, water, let’s par-tay!”

2

It’s the metallic form that reacts, not the ion. After ou’ve thrown the sodium metal in the water, it produces sodium hydroxide (NaOH) plus hydrogen, plus heat. The heat ignites the hydrogen gas. Th NaOH goes into solution as Na+ and OH-. The sodium ion clearly doesn’t react in water to give that big effect, since it’s one of the products o the big pop.

3

Sodium, in its elemental form, is quite reactive because it reaches a more stable configuration by giving up an electron to form sodium ion, Na[sup]+[/sup]. Sodium ion, already in the most stable form, thus has no inclination to react with water. It is already in the most stable configuration, with one fewer electron than elemental, metallic sodium.

(Let’s see, it’s mid-September. That’s about right for this topic in the school-year sequence…)

4

It’s because the sodium ion doesn’t have its 3s[sup]1[/sup] electron anymore that it is stable in water. Or conversely, the 3s[sup]1[/sup] electron in a sodium atom is what makes it so chemically reactive.

5

Hey! I resemble that remark! :stuck_out_tongue:

I am back in school, but I asked out of genuine curiousity…not homework scrounging.

6

Na[sup]+[/sup] doesn’t react with water because it has already partyed til it can’t party no more. Sodium metal is oxidized by (loses an electron to) water to the sodium ion Na[sup]+[/sup]. Once the electron is gone, there is nothing left to react with more water molecules. For the Na[sup]+[/sup] ion to react again it’d have to lose another electron, Na[sup]+[/sup] -> Na[sup]2+[/sup]. That reaction does not happen under normal conditions. (Na[sup]+[/sup] is oxidized or ionized to Na[sup]2+[/sup] in places like the atmospheres of stars, but the temperatures there are well above the boiling point of water.)