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View Full Version : Help with calibration solutions for pH Meter



Ian Gordon Bilson
27-Jan-2013, 19:54
I have close to zero math,so bear with me.
I need to prepare acid and base solutions to calibrate the meter.
I have Sodium Hydroxide (Reagent grade,97%+pure,Mol.wt 40.00),and
Glacial Acetic acid available.
How much of each,in ml/grams would I need, made up to 200ml total,to produce
pH's of 4 and 8 ?

I have searched elsewhere without success.

Paul Hoyt
28-Jan-2013, 23:28
Your first problem is Acetic Acid is weak acid and you can not buffer it with NaOH to a pH of 4. You will need other chemicals to make buffers that will resist pH changes and remain stable. I suggest you try to locate some of the compounds listed in this link: (Preparation of pH buffer solutions); delloyd.50megs.com/moreinfo/buffers2.html

It is also possible to buy prepared pH buffer solutions from Carolina Biological; carolina.com

Paul