Separation of mixture of solids by physical methods can be based on differences in the following except

Explanation

Physical methods of separating mixtures rely on differences in the physical properties of the substances in the mixture. These properties can be observed or measured without changing the chemical identity of the substances.

Differences in melting point can be used to separate solids. If one solid melts at a lower temperature than another, you can heat the mixture to that temperature. The one with the lower melting point will melt and can be poured off, leaving the other solid behind.

Differences in solubility allow separation by dissolving. If one solid dissolves in a particular solvent but the other does not, you can add the solvent, filter out the undissolved solid, then evaporate the solvent to get back the dissolved solid.

Differences in particle size allow separation by sieving. If the particles of one solid are larger than those of another, passing the mixture through a sieve separates the larger particles from the smaller ones.

Molar mass alone cannot be used to physically separate a mixture of solids. Molar mass is a property of individual molecules or formula units, and it does not directly translate into an observable physical difference that can be exploited for separation. Two substances could have very different molar masses but similar particle sizes, solubilities, and melting points.