Now I know it's something related to the fact that $\ce{CCl4}$ does not have a net dipole moment but I can't connect the dots.


In order for a substance to dissolve, the free energy change for the dissolution must be negative. For the enthalpy change to be negative the heat of solvation (the solvent solvating the solute) must be greater in magnitude than the heat needed to break up the forces holding the solid solute together (in the case of NaCl lattice energy). The entropy change of the solution process is accounted for by the gain in entropy from breaking up the solid and the loss of entropy from organizing solvent around the solute. In forming most solutions, the entropy change is positive.

In this case the ability of carbon tet to solvate sodium and chloride ions is too low to make up for the lattice energy. Carbon tet is nonpolar. A good solvent for NaCl would be polar and the negative end of the solvent would surround sodium ions and the positive end would surround chloride ions.


|improve this answer|||||

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.