How do I prepare a 3% solution from NaClO departing from a solution of 10 ° chlorine?

Comment: A 3% solution is not as common compared to the 1% solution. Nevertheless, it appears to the Department of Dentistry UG a solution recommended from 2.5 to 5%.

Solution: (worked out with pharmacist P. Fransoo) With the data from the Solvay website, the following calculation can be made to make a 3% solution of hypochlorite starting from a 10 ° chlorine solution.

10 ° chlorine means 31.7 g of active chlorine per litre corresponding to 31.7/0.953 = 33.26 g NaOCl per litre. For making 1 L of NaOCl solution to 3% then 1000x30/33.26 = 902 ml solution with water should be diluted to 1000 ml.

is also customary to use 1/3 L of the commercially available product with 2/3 L of water to obtain 1 L solution ready to be used. This corresponds roughly to the 1% NaOCl solution (see question: Multiple dentists ask for a 3% sodium hypochlorite solution).