1. The problem statement, all variables and given/known data Which of the following will react with Br2 but not with I2? A OH− B SO3 2− C Fe2+ D Mn2+ 2. Relevant equations N/A 3. The attempt at a solution The answer given in the marking scheme is C, and I can't figure out how to come to that conclusion. Is it something to do with electronegativity? London dispersion forces? My exam is tomorrow morning and I'm freaking out about this just a little...!