(R)-2-Bromobutane is reacted with a solution of NaI: however, the label is blurry and it is unclear what solvent the NaBr is dissolved in. Upon isolation of the product it appears to be optically inactive. Explain what must have happened mechanistically. If your goal is to synthesize (S)-2-iodobutane, how might you modify the experiment to ensure that you do so in your next attempt?