Sale or mortgage of decedent‘s real estate.) (a) By leave of court and upon such terms as the court directs, a representative of a decedent’s estate may sell or mortgage any real estate or interest therein to which the decedent had claim or title, including the oil, gas, coal or other mineral interest therein, when it is necessary for the proper administration of the decedent’s estate.
     (b) Real estate specifically bequeathed or directed by the testator not to be sold may not be sold or mortgaged unless necessary for the payment of claims, expenses of administration or estate or inheritance taxes or the proper distribution of the estate.