Peroxide solution

[mk12]

I made 0.5% H2O2 from 30% H2O2 by diluting 1.66 ml into 100 ml distilled water. Did I do it right because my results shows I did not?

[tom jupille]

To one significant figure (0.5%), that looks right to me. If you wanted to be more precise, you'd have to specify whether you wanted percentage by weight or by volume and (for the former) take into account the specific gravity, but those refinements would only show up in the second figure.

[AdrianF]

What do you mean when you say your results show your dilution was incorrect?

If you mean you assayed the hydrogen peroxide after dilution and found the concentration to be less than expected; that is easily explained as hydrogen peroxide is unstable and should be assayed before use.