Is the dissolution of sodium chloride in water a physical or chemical change?

1 Answer

It is a physical change. When the NaCl dissolves, the Na and Cl ions do break apart. It is not a chemical change because no new chemical bonds are formed. It can also be considered a change of state.

NaCl(s) -> NaCl(aq)

It is a very common misconception that this process is a chemical change. According to data from AAAS 21% of high school students believe that dissolving is a chemical change. I know an AP Chem teacher who teaches that it is a chemical change, I've tried to explain to him why it is a physical change to no avail. :(

You can see info about this misconception and others at the following website under the topic "Many substances react chemically in predictable ways..."

http://assessment.aaas.org/topics/SC#/,tabs-100/2,tabs-102/2

Noel P.