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Topic: Manual Titration End Point  (Read 1403 times)

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Offline znaes97

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Manual Titration End Point
« on: July 21, 2022, 01:00:13 PM »
Hello everybody,

I have to do a handful of daily titrations for work. One of the titration procedures says to add titrant until the solution goes clear. The solution, however, never goes fully clear, only to a light peach color. Using phenolphthalein indicator, is this peach-like color the proper end point? Should I end the titration as soon as it starts going peach? Thank you in advance, any help is greatly appreciated.

Offline Hunter2

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Re: Manual Titration End Point
« Reply #1 on: July 21, 2022, 01:06:48 PM »
You stop until pink colour disappears, depending on the matrix it can be yellow, peach or colourless.
This has to stand at least 1 min. If colour comes back add again one drop of the acid. in comparison you can use a pH Probe to see what is pH if pink colour disappears.

Offline znaes97

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Re: Manual Titration End Point
« Reply #2 on: July 21, 2022, 01:27:37 PM »
You stop until pink colour disappears, depending on the matrix it can be yellow, peach or colourless.
This has to stand at least 1 min. If colour comes back add again one drop of the acid. in comparison you can use a pH Probe to see what is pH if pink colour disappears.

So once the primary starting color has changed, that's the end point? Related to that, some of the titrations start clear, go cloudy, then end pink. This end point would be once the cloudy starts going pink, correct? Thank you for your help

Offline Hunter2

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Re: Manual Titration End Point
« Reply #3 on: July 21, 2022, 01:38:48 PM »
Correct if you titrate to alcaline,  colour change from colourless to pink. Cloudy doesnt matter. Maybe do test to get a feeling use 10 ml 0.1 n HCl and titrate it with 0.1 n NaOH and vise versa .The consumption should be 10 ml

Offline znaes97

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Re: Manual Titration End Point
« Reply #4 on: July 21, 2022, 01:52:19 PM »
Correct if you titrate to alcaline,  colour change from colourless to pink. Cloudy doesnt matter. Maybe do test to get a feeling use 10 ml 0.1 n HCl and titrate it with 0.1 n NaOH and vise versa .The consumption should be 10 ml

Thank you so much for that information and for responding so fast. Have a nice day!

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