Ian Roe wrote:
> Hi: I'm not the greatest when it comes to titration mathematics. Can > someone here show me the formula for dilution. I knew how to do this > once but I just can't remember now. Problem: wish to put an unknown > volume of 35% H2O2 into a 250 ml and a 500 ml container and fill with > distilled water to obtain 3%. > That is pretty easy. You want 500 ml of 3% H2O2, so you want the > container to contain .03*500 = 15 ml of H2O2 with the remainder water. > Since the H2O2 is 35% to start with you will have to start out with > 15/.35 ml of the 35% H2O2 or just under 43 ml. > > So put just under 43 ml of your 35% H2O2 in the 500 ml container, and > fill with water to 500 total volume. Now that will be a volume > percentage. For a weight (mass) percentage, then you would have to > work with weights, but I think the 35% H2O2 is close enough to the > mass of water to not worry about it. > > Marshall > > > Equipment: 35% H2O2, 250 and 500 ml containers and a 30 ml measuring > cup divided off in 5 ml lines, drams at the 1/4 oz markers, 1/4 oz > markers - and of course distilled water. Thanking you in > advance. IanRoe
