# Homework Help: Gravimetric factor

1. Nov 26, 2007

### klively

How do you work these problem? I need each step Please.

1. The concentration of the present dye is 95%, and the concentration of the new dye is 76%. How many grams of the new dye are needed to make a 100 ml of 0.3% solution with the same staining intensity as what was obtained with the old dye?

2. The concentration of the present dye is 82%, and the concentration of the new dye is 96%. How many grams of new dye are needed to make up 250 ml of 0.5% solution with the same staining intensity as what was obtained with the old dye?

3. The concentration of the present dye is 76%, and the new dye is 95%. How many grams of the new dye are needed to make 50 ml of 5% solution with the same staining intensity as what was obtained with the old dye?

klively

2. Nov 26, 2007

### symbolipoint

Each of those questions is the same general question; the only things which change are the values. If you solve one question symbolically, you solve all of them.

You seem to show a difficulty with "present dye" and "new dye". If these are different dyes, then you can not be sure that mass for mass each will produce a dyeing of the same strength. (That is, mass for mass of the dye by itself, excluding the solvent)

Are you certain that you need "Gravimetric Factors"? The gravimetric factor is used for quantitative analysis by precipitation. You could probably use the idea in comparing masses for other purposes, too.

3. Nov 27, 2007

never mind.