Answer:
Dear Muhammad Saleem Kalhoro,
you can use the formula C1V1=C2V2 formula where C1 is concentartion of stock solution, V1 is volume of stock solution, C2 is concetration which you required and V2 is volume which you required. for example u want to make 100mL of 3% H2O2 from 6% H2O2. use this formula u will find that add 50 mL distilled water to 50 mL of 6% H2O2.
Good luck
