if sodium chloride (NacL solid) ionizes in water (H2O) what happens?

Question

chemistry
sodium chloride
ionization
water
physical change
chemical change

Answer 1

Sodium Chloride (NaCl) is an ionic compound made up of a Na+1 ion and a Cl-1 ion.

Water (H2O) is a polar solvent due to the nature of the bonds within the molecule. Oxygen, being more electronegative, pulls the electrons farther away from the Hydrogen atoms as well as the fact that Oxygen has 2 lone pairs of unbonded electrons, this combination makes water an excellent solvent for polar and ionic substances.

The Oxygen atom in water develops a slight negative charge while the Hydrogen atoms develop a slight positive charge.
Since the atoms have these slight charges, they are attracted to the full charges on the Sodium and Chloride ions in NaCl.
What happens is the polar water molecules collide with the undissolved NaCl solid and "stick" to the ions and surround them in a way. The positive Na+ ions get surrounded by the slightly negative Oxygen end of the water molecule, and the negative Cl- ions get surrounded by the slightly positive Hydrogen end of the water molecule.

What this does it break NaCl up into its ions in solution,
NaCl (s) ---H2O--> Na+ (aq) + Cl- (aq)
Solid Sodium Chloride dissolves in water to form Na+ and Cl- ions in aqueous solution.
NaCl is a strong electrolyte, meaning that in solution, it will complete break up into ions. A weak electrolyte (like vinegar / acetic acid) it will break up into ions, but not completely.

Not all substances will behave this way. Sugar, for example, is a non-electrolyte, it will not ionize at all in solution,
C12H22O11 (s) ----H2O----> C12H22O11 (aq)


Electricity has nothing to due with the ionization of Sodium Chloride as it dissolves in water, but once the NaCl has dissolved, an electrical current will be able to flow through the solution.

Answer 2

This is a questionof symantics and not really chemistry. What is happening is that the Sodium and Chlorine ions are dissociating in the water because their lattice energy is less than the kinetic energy of the water molecules. So the water is able to break the ions away from their electromagnetic attraction to the salt crystal. That sort of process is usually not called a chemical change although I can certainly see some professor calling it that to emphasize that the ions in dissociation have caused the halo of electrically oriented water molecules around each ion. With sodium ions, which are positive, you would have the lone pairs of the oxygen atoms in water pointing to the sodium ion. With Chloride ions, which are negative, you would have the hydrogen side of the bent water molecules oriented towards the chloride ions. This will change the physical, and to a minor degree, the chemical properties of the solution. But most people would not consider it a chemical change.

Answer 3

In its solid form sodium chloride lines up in grid like a checkerboard with sodium ion chlorine ion, sodium ion, chlorine ion. Water breaks up this grid a little and the ions are free to move about, but they still kind of line up in the water sodium ion, chlorine ion. the big difference only happens when someone puts a DC current in the water, then the chlorine ions go one way and the sodium ions go the other. when that happens a chemical change usually takes place and sodium hydroxide is formed on one side of the water and hydrochloric acid is formed on the other as the ions try to re-arrange themselves with water molecules.

Answer 4

As NaCl (solid) is an ionic lattice you could say there was very little change. But the charges are separated and the ions solvated in water. I guess a chemistry teacher would call it a physical change, but I can't really see the virtue in such labels.

Answer 5

NaCl is just table salt, so if it dissolves in water, it's just a physical change. I don't see how it can ionize in water, unless you pass an electrical current through it.

Answer 6

the ions are solvated that is to say the positive charged Na is surrounded by O part of H2O, and the Cl is surrounded by the H part of H2O

Answer 7

chemical change, the boiling point was raised.