Reactions of Bromine |
Reactions with water |
Bromine reacts with water to produce hypobromite, OBr-. The pH of the solution determines the position of the equilibrium.
|
Br2(l) + H2O(l)OBr-(aq) + 2H+(aq) + Br-(aq) |
Reactions with air |
Bromine is not reactive towards oxygen or nitrogen but it will react ozone at -78°C to form the unstable compound bromine(IV) oxide.
|
Br2(l) + 2O3(g)O2(g) + 2BrO2(s) |
Reactions with halogens |
Bromine reacts with chlorine in the gas phase to form the interhalogen species BrF. The product is difficult to obtain pure since BrF disproportionates
at room temperature to form bromine, Br2, and BrF3 and BrF5.
|
Br2(g) + F2(g)2BrF(g) |
3BrF(g) + Br2(l)BrF3(l) |
5BrF(g) + 2Br2(l)BrF5(l) |
Under more forceful conditions, excess fluorine reacts with bromine at 150°C to form the interhalogen species BrF5.
|
Br2(l) + 5F2(g)2BrF5(l) |
Chlorine reacts with bromine in the gas phase to form the unstable interhalogen species bromine(I) chloride, ClBr.
|
Cl2(g) + Br2(g)2ClBr(l) |
Bromine reacts with iodine at room temperature to form the interhalogen species bromine(I) iodide, BrI.
|
Br2(l) + I2(s)2IBr(s) |
Reactions with bases |
Bromine reacts with hot aqueous alkali to produce bromate. Only one sixth of the total bromine is converted in this reaction. |
3Br2(g) + 6OH-(aq)BrO3-(aq) + 5Br-(aq) + 3H20
|
|
Reduction Potentials |
Balanced half-reaction |
E0 / V
|
Br2(l) + 2e-2Br- |
+1.065 |
Br2(aq) + 2e-2Br- |
+1.087 |
Br3- + 2e-3Br- |
+1.05 |
HBrO3 + 5H+ + 6e-Br- + 3H2O
|
+1.42 |
3HBrO3 + 15H+ + 16e-Br3- + 9H2O
|
+1.462 |
2BrO3- + 12H+ + 10e-Br2(l) + 6H2O
|
+1.52 |
BrO3- + 6H+ + 6e-Br- + 3H2O
|
+1.44 |
BrO3- + 3H2O + 6e-Br- + 6OH- |
+0.61 |
2HBrO2 + 10H+ + 10e-Br2(l) + 6H2O
|
+1.48 |
HBrO3 + 4H+ + 4e-HBrO + 2H2O
|
+1.46 |
HBrO3 + 3H+ + 4e-BrO- + 2H2O
|
+1.33 |
2HBrO + 2H+ + 2e-Br2(l) + 2H2O
|
+1.59 |
2BrO- + 4H+ + 2e-Br2(l) + 2H2O
|
+2.09 |
2BrO- + 2H2O + 2e-Br2(l) + 4OH- |
+0.45 |
BrO- + H2O + 2e-Br- + 2OH- |
+0.76 |