Mechanisms for (-5[1])this type of reaction (-5[1])are discerned by the parameter m in the Grunwald–Winstein equation. It’s not alkylation, but the presence of sulfur in mustard gas increases the rate of one of these (-5[1])reactions in a classic example of anchimeric (“an-kye-MER-ic”) assistance. (-5[1])Carbocation (“carbo-CAT-eye-on”) intermediates act as Lewis acids in one of these (-5[1])reactions. (10[1]-5[1])In one type of this reaction, (10[1])inversion of (10[1])configuration (10[3])occurs (10[4])due to (10[1])a (10[1]-5[1])“backside (10[1])attack.” (10[17]0[1]-5[1])A pentavalent (10[1]-5[1])transition state occurs (10[1])in one type of this reaction (10[1])whose name indicates that it is bimolecular. (10[2])High temperatures (10[1])or bulky bases cause eliminations to (-5[1])be (0[1])favored over these reactions. (10[4])For 10 points, the nucleophilic SN1 and (0[5])SN2 mechanisms exemplify (10[1])what type of (10[1])reaction, (10[1]-5[1])in which one group of a compound is exchanged (10[1]-5[1])for another? (10[3])■END■ (10[3]0[2])