PH Solutions

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sammy
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PH Solutions

Post by sammy »

Hi Everyone

Just wondering what you all use to make up variouse ph Solutions ??? I have been asked to make up ph 3, 4, and 6 solutions just thought i would pick your brains and see how everyone else does it :D

Sammy
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Rowyrow
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Re: PH Solutions

Post by Rowyrow »

Does you teaher want Buffer solutions or just solutions with a specific pH?
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sammy
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Re: PH Solutions

Post by sammy »

just specific ph solutions they are doing mock river water
RosalieM
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Re: PH Solutions

Post by RosalieM »

I have just written in a different thread to bring it to your attention. Haven't merged them as I don't know that it really is what you are looking for. Hope it is of some use though!
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Rowyrow
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Re: PH Solutions

Post by Rowyrow »

You could always try the buffers
this has come from "The Laboratory" by Barbara Dungy

Ph range 3.0-6.2 citrate buffer

prepare two aqueouse solutions of
0.1 M citric acid (19.21 g per litre)
0.1M sodium citrate (29.41 g per litre)

to make appropriate buffer add solutions in quantities shown. Make up to 100ml with distilled water.

pH 3) 46.5ml 0.1M citric acid and 3.5ml 0.1 M sodium citrate
pH 4) 33.0ml 0.1M citric acid and 17.0ml 0.1M sodium citrate
pH 6) 9.5ml 0.1M citric acid and 42.8ml 0.1M sodium citrate
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fiona
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Re: PH Solutions

Post by fiona »

I made up my own buffering solution using the Henderson-Hasselbach equation. Then using dilute NaOH and HCl, adjusted it to the pH I wanted. But if you don't need buffers you could use pH = -log[H+] to work out the concentrations of acid needed. That may be a little too mathy, though, if 've never done it before.
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rae
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Re: PH Solutions

Post by rae »

I have this list that I acquired off chemtalk a while ago
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lada
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Re: PH Solutions

Post by lada »

Have a look at thread under pH solutions on 27/4/07.
There is a recipe for ph 1-14 using HCl and NaOH. It is very easy to prepare.

Lada :clap3:
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kimmy
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Re: PH Solutions

Post by kimmy »

This is how we make up all our pHs when required to do them. :thumbup:

we use this mainly for our years 9 and 10 as a station experiment for them to try to identify which is which as we put them in bottles labled A to N and mix them so say pH 4 might be in bottle K and they have to identify them. It takes them time to work them all out and get the full range.

Anyway hope it is of some help for you.

KIMMY
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Jen Jen
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Re: PH Solutions

Post by Jen Jen »

Hope this helpspH solutions
Standard pH solutions may be easily prepared using the following recipes:
pH2
0.01M hydrochloric acid
 
 
pH3
80mL  0.1M citric acid
plus
20mL 0.2M disodium hydrogen phosphate
pH4
62mL  0.1M citric acid
plus
38mL 0.2M disodium hydrogen phosphate
pH5
48mL  0.1M citric acid
plus
52mL 0.2M disodium hydrogen phosphate
pH6
37mL  0.1M citric acid
plus
63mL 0.2M disodium hydrogen phosphate
pH7
18mL  0.1M citric acid
plus
82mL 0.2M disodium hydrogen phosphate
pH8
  3mL  0.1M citric acid
plus
97mL 0.2M disodium hydrogen phosphate
pH10
0.1M sodium hydroxide
 
 
These solutions are sufficiently accurate for use in the cell membrane activity in Biology and also for general pH testing. 
Thanks to Diana Hackett - Kent Street S.H.S. for this information.
from RTG wa site sols.
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sammy
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Re: PH Solutions

Post by sammy »

Thanks everyone for all your useful info :clap3:
My solutions are all made up and ready to go now \:D/
I used the HCI recipe and seemed to work a treat :wink2:
Hopefully should keep me in the teachers good books for a while :wub:
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lada
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Re: PH Solutions

Post by lada »

I got the recipe from Kimmy and have used ever since.
Thanks
Lada
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smeee
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Re: PH Solutions

Post by smeee »

Thanks Rae
I have just made up the solutions and used them for the Bio prac "Effect of CO2 on the pH of water", to calibrate the datalogger. ...also tested with Universal indicator...excellent !!!!
Merilyn1
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Making buffers

Post by Merilyn1 »

I need a large quantity of pH buffers for an Extension Science project, so my HT has asked me to make them. I've found the pages of recipes in The Laboratory, so think I've got that far, but would appreciate anyone else's suggestions. I don't have time to order anything in.

My other question: as they have a short shelf life, (from internet searching, especially the higher pH value), if I make the solutions separately, and leave mixing them until needed, will that extend their life? Is the deterioration a result of mixing the two components? Am I just wasting my time and I should just mix them together now? The Laboratory says to use fresh solutions.

Appreciate your help
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Labbie
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Re: PH Solutions

Post by Labbie »

Merilyn 1 their are so really great ideas in this thread.
Regards Labbie

Lab Manager/Lab Tech, mind reading etc etc
Now retired :wub:
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