Question

Use the activity series below to predict whether the following reactions will take place.

Activity series from most to least reactive: Upper F Subscript 2; Upper C l Subscript 2; Upper B r Subscript 2; Upper I Subscript 2.

Cl2 + 2RbI → 2RbCl + I2



I2 + NiBr2 → NiI2 + Br2

Answer 1

Use the halogen activity series (F2 > Cl2 > Br2 > I2): a halogen will displace a less reactive (lower) halide from a salt, but not a more reactive (higher) one.

1) Cl2 + 2RbI → 2RbCl + I2
- Will occur. Cl2 is above I2, so it oxidizes I– to I2.
- Net ionic: Cl2 + 2I– → 2Cl– + I2

2) I2 + NiBr2 → NiI2 + Br2
- Will not occur. I2 is below Br2 (less reactive), so it cannot displace Br– to make Br2. (The reverse process, Br2 displacing I–, would be favorable.)