# Thread: B&S Ammonium Dichromate 10% concentration

1. ## B&S Ammonium Dichromate 10% concentration

B&S sent me an ammonium dichromate in 10% concentration solution. Now, if I take this one liter (10% ammonium dichromate) and mix it with one liter water, would it bring the concentration down to 5% ?

2. ## Re: B&S Ammonium Dichromate 10% concentration

The way I look at it Nasser is that if you have something marked "10% solution" then that means that there is 10 grams of whatever in every 100mL of the solution. So if you have a liter of it there is 100gms of the chemical disolved in that liter. If you take that one liter and transfer it to a 2 liter graduate and pour in 1 liter of distilled water into it you end up with 2 liters of water with the original 100 grams of the chemical disolved in it - you didn't add any more of the chemical. So you now have 100 grams in 2 liters or 50 grams per liter or a 5% solution assuming of course that you mixed it well. (100/2000 * 100 = 5%).

Thomas

Yes.

4. ## Re: B&S Ammonium Dichromate 10% concentration

Thank you Thomas for the good info! Thanks Andrew, I am glad to see you here in this forum.. I really like your video at youtube!

5. ## Re: B&S Ammonium Dichromate 10% concentration

One more thing please! 5ml acetone + 5ml (10% Ammonium) would that equals 5% concentration?

6. ## Re: B&S Ammonium Dichromate 10% concentration

Originally Posted by Nasser
One more thing please! 5ml acetone + 5ml (10% Ammonium) would that equals 5% concentration?
Yes. Personally, when I am brush sensitizing carbon tissues I do not compute the final concentration -- instead I base it on the volume of my stock solution per square inch of tissue. For example; 5ml of an 8% Am dichro solution for 100 sq inches of tissue -- which I then dilute 1 part to 3 parts acetone before applying it to the tissue. When I sensitize an 14x17 tissue, I use 12ml of AM stock solution added to 36ml acetone.

Vaughn

7. ## Re: B&S Ammonium Dichromate 10% concentration

Thanks Vaughn!

8. ## Re: B&S Ammonium Dichromate 10% concentration

Many ways of doing it! If one uses a bath of dichromate solution, then the final concentration is important.

PS...do not dilute the whole bottle of 10% down to 5%...unless you are standardizing your process using digital negs. Perhaps you have tighter control, but my camera negs tend to be exposed in a wide variety of light and my negs tend to end up all over the place (in a controlled sort of way, LOL!) and it is nice to have 6 and 8 percent solutions of AD for those negatives for those real robust negatives! Actually I have standardized on 8% for my own work, and 4% for workshops using digital inkjet negs.

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