Ferroxyl agar....brain freeze moment

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linotas
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Joined: 21 Mar 2011, 22:39
State/Location: TAS

Ferroxyl agar....brain freeze moment

Post by linotas »

So I'm making up the ferroxyl agar for the corrosion prac and it needs 10% alcoholic phenolphthaleine indicator solution. Is that a 10% phenolphthalein solution or 10% ethanol added to a normal 1-2% phenolphthaleine indicator solution?
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Labbie
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Re: Ferroxyl agar....brain freeze moment

Post by Labbie »

Ferroxyl Gel, or agar. 7.5g agar, 500ml distilled water, 10ml 0.1M Phenolphthaiein or 1%, 75ml Potassium Ferricyanide III 0.1M, 5ml Sodium Chloride Saturated.

Boil water & agar, remove from heat, when cool to about 30c add phenolphthalein, Potassium Ferricyandie, then Sodium Chloride, a few drops of KOH turns the gel pink, HCL will bring it back to clear.

Do hope this helps you.
Regards Labbie

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linotas
Posts: 659
Joined: 21 Mar 2011, 22:39
State/Location: TAS

Re: Ferroxyl agar....brain freeze moment

Post by linotas »

Thanks Sue, We have a slightly different recipe but essentially the same. I went with the 10% solution and have already done a test plate and it works really well :D Last year it didn't so both myself and the teacher are very pleased.
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