The question is, why is that so? Well, what types of bonds do we have between two non polar molecules? Well, typically, the bonds are London dispersion forces. They're the attractions that exist as a result of the instantaneous dipole moments that exist along this entire hydrocarbon chain. And so, because longer fatty acids contain more of these carbon atoms and more h atoms, we have more lung and dispersion forces within the longer within the longer fatty acid solution. So as the length increases, the melting point increases as a result of more or Londondized version forces, a stronger intermolecular traction between those adjacent fatty acid molecules.