The ro– group is the nucleophile. think about which group in the alkyl halide (iodoethane) is the leaving group. keep in mind that the leaving group may be one atom or a group of atoms.

Consider this reaction taking place in a closed 2 liter container: 2so2(g) + o2(g) → 2so3(g) if the volume of the container is decreased to 1 liter, what will happen to the equilibrium of the reaction? it will shift left. it will shift right. it will remain constant it will decrease by half