Eriochrome Black T

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starfish
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Eriochrome Black T

Post by starfish »

Hi everyone,

Can anyone tell me a recipe for making up Eriochrome Black T indicator for a water analysis prac? I don't have fancy stuff like triethanolamine or hydroxylamine hydrochloride in the recipes I've found so far, and I'm hoping there's a simple recipe that will work for these water hardness tests.

Thanks,
Kylie
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Robb
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Re: Eriochrome Black T

Post by Robb »

Hi All,

I prepare the solution by adding 0.2g of the dyestuff in 15mL of triethanolamine with the addition of 5mL of ethanol.

That will get you out of trouble.

Must be doing Metal determination.

Cheers,

Robb.....
Dr Robert Crosdale. MRACI. NSS. NSSA. NASA.
Ph.D (Chem), Post Grad Ph.D (Physics), M.Ed, B.Sc (Hons), Dip. Appl. Sc. (Chem)
Lake Munmorah High School.
University of New England.
University of New South Wales.
University of Newcastle.

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pkij
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Re: Eriochrome Black T

Post by pkij »

Recipe I have used from a Chemistry text book is;
Dissolve 0.2g powder in 15ml commercial NH3 and add 5ml ethanol. (I assumed commercial NH3 was conc. ammonia.)

This was for determination of water hardness using EDTA, it did work, however the solution does not keep for long. We could'nt work out why the prac was not working, I made up fresh solutions and yay it worked! :thumbup:
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Narelle01
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Re: Eriochrome Black T

Post by Narelle01 »

its this time of year.....
thought i would get this thread up - just in case, someone else, like me is sratching her head working this prac out....

i need 80mls of this indicator.

You know when I am cooking at home, if i don't have something for a reciepe, i just leave it out, but i don't think thats going to work here....worse luck!
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Jazz
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Re: Eriochrome Black T

Post by Jazz »

Eriochrome Black T Indicator
1% alcoholic: Dissolve 1 g of eriochrome
black T in 80 mL of 95% ethyl alcohol,
dilute to 100 mL with 95% ethyl alcohol.
(indicator for EDTA titrations)


http://www.flinnsci.com/Sections/Safety ... N_PREP.pdf

I think this link was posted before :-)
Cheers Jazz
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Narelle01
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Re: Eriochrome Black T

Post by Narelle01 »

is that correct Jazz?
kjt
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Re: Eriochrome Black T

Post by kjt »

Hi,
We have used a salt/solid for several years now (and it keeps for years). The students just add a very small amount of solid to the solution instead of a prepared liquid indicator (which was a pain as it had to be fresh). We got the recipe from the internet and from memory it was:

1g Eriochrome T-Black and 100g sodium chloride crushed together.

(We only made up 20g, but even 10g would be plenty) Very simple and works a treat.

Cheers,
Kirsty
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Narelle01
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Re: Eriochrome Black T

Post by Narelle01 »

it came up a very deep red - is that right?
kjt
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Re: Eriochrome Black T

Post by kjt »

Our indicator/salt crushed solid is pale purple. When added to three water samples tested today, they started out a deep pink (almost cranberry) then went through purple to blue when titrated with EDTA (using method in Conquering Chemistry HSC).
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smeee
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Re: Eriochrome Black T

Post by smeee »

I have just made it up as per recipe in Chemistry Contexts :

Dissolve 0.5g of eriochrome black-T in an 80ml ethanol/20ml distilled water mixture.

It worked ok
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Narelle01
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Re: Eriochrome Black T

Post by Narelle01 »

I used the recipe above, it took ages to dissolve and the colour deepened over night -oh well the prac is on now, while i recover from mixing the sodium iodide solution without a fume cupboard.
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Jazz
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Re: Eriochrome Black T

Post by Jazz »

To be honest this is first time I made it 8-[ . No one complained It must be working. It has to be fresh though.I use recepies from this website and never had any problems
Cheers Jazz
mtg
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Re: Eriochrome Black T

Post by mtg »

Is there a substitute for Eriochrome Black T. I don't think I have it.
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Westlab - Alice
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Re: Eriochrome Black T

Post by Westlab - Alice »

If it helps, we sell EL024-25G Eriochrome Black T LR. This is a 25g bottle. CAS: 1787-61-7
ALICE ELFORD
Product Manager | Product Development

P 1800 358 101
E alice.elford@westlab.com.au
W www.westlab.com.au

LinkedIn: https://www.linkedin.com/in/alice-elford/
mtg
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Re: Eriochrome Black T

Post by mtg »

Thanks Alice, I'll put it on my list for our next order.
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Westlab - Alice
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Re: Eriochrome Black T

Post by Westlab - Alice »

mtg wrote: 05 Aug 2020, 14:59 Thanks Alice, I'll put it on my list for our next order.
Look forward to it :D
ALICE ELFORD
Product Manager | Product Development

P 1800 358 101
E alice.elford@westlab.com.au
W www.westlab.com.au

LinkedIn: https://www.linkedin.com/in/alice-elford/
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