How do you make a 0.05 M bromine solution?

Bromine (0.05 M) 

Molecular formula: Br2  

Molecular weight: 159.81 

Preparation: Dissolve 3 g of potassium bromate and 15 g of potassium bromide in sufficient water to produce 1000 mL. 

Standardization: Pipette 25.0 mL of the solution into a 500 mL iodine flask and dilute with 120 mL of water. Add 5 mL of hydrochloric acid and insert the stopper in the flask and shake it gently. Add 5 mL of potassium iodide solution again insert the stopper and allow it to stand for 5 minutes in the dark. Titrate the liberated iodine with 0.1 M sodium thiosulphate using 3 mL of starch solution, added towards the end of the titration, as an indicator. Store the solution in dark amber-colored, glass stoppered bottles. 


Br2 + S2O2−3 + H2O → 2Br + 2SO2−4 + 2H+


1 mole of Na2S2O3 ≅ 1 mole of bromine 

1000 mL of 1M Na2S2O3 ≅ 159.81 g of Br2  

1 mL of 0.1 M Na2S2O3 ≅ 0.01598 g of Br2

Make sure you also check our other amazing Article on: How do you standardize 0.05 M potassium iodate solution?
Sharing Is Caring:

Leave a Comment