Question

Without performing any calculations, determine whether the entropy of the system increases or decreases in the dissolution of table salt:

NaCl(s) → NaCl(aq)

1.) Unable to determine

2.) decreases

3.) The entropy does not change.

4.) increase

Answer 1

Answer option 4) Increases.

Entropy - degree of disorder or randomness in the system.

Entropy for gas >>> liquid >> solid

In solid ions or atoms are fixed in a particular lattice hence disorderness will be minimum.

whereas in solution ions will be in moving in all direction hence disorderness will be higher in solution than in solid.

And in gas phase moving of ions or atoms will be very fast than sloution.

So

NaCl(s) → NaCl(aq) entropy of aq solution of NaCl will be higher than NaCl in solid phase.