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Hi all, need to make up solutions of required pH: 2,4,6,8,10.
I have a method to prepare these as buffers, using HCl and potassium hydrogen phthalate, and sodium hydroxide and boric acid with potassium chloride.
This is very time consuming. Any ideas?
Lada

Hi
Just buy the buffer tablets -they are a lot cheaper than the solutions.
Hope this helps
rhonda

Thanks, I do use them for calibrating pH meters.but for this I do not need buffers, but pretty accurate solutions for biology practicals. I just wanted to know, what concentrations of different acids and bases (if any)will give me the above pH
Lada

Hi there,
here is the way to make your pH range
hope this is of some use
Making PH Solutions

To Make 200ml of each solution

To make a 200ml solution of PH1 to PH7
PH1 = .1 mol HCL 220ml (Base Solution)
PH2 = 20 ml .1 mol HCL + 180ml distilled Water = 200ml = PH2
PH3 = 20 ml PH2 Solution + 180ml distilled Water = 200ml = PH3
PH4 = 20 ml PH3 Solution + 180ml distilled Water= 200ml = PH4
PH5 = 20 ml PH4 Solution + 180ml distilled Water =200ml = PH5
PH6 = 20 ml PH5 Solution + 180ml distilled Water =200ml = PH6
PH7 = Distilled water should have a PH of 7

To make a 200ml solution of PH14 to PH8
PH14 = 1.0 mol NaOH 220ml (Base Solution)
PH13 = 20ml NaOH + 180ml Distilled Water = 200ml PH13
PH12 = 20ml PH13 + 180ml Distilled Water = 200ml PH12
PH11 = 20ml PH12 + 180ml Distilled Water = 200ml PH11
PH10 = 20ml PH11 + 180ml Distilled Water = 200ml PH10
PH9 = 20ml PH10 + 180ml Distilled Water = 200ml PH9
PH8 = 20ml PH9 + 180ml Distilled Water = 200ml PH8
PH7 = Distilled water should have a PH of 7

Hi kimmy, thats exactly what I need. thanks a lot.
Lada

Hi Lada,
It is the easiest way and most accurate way I have found to do the pH range - and it works.

Thanks kimmy, I have printed it and copied it and pasted it into my work book, so I will never lose it. I have prepared it this avo all ready for monday. Your a life saver, or at least time saver.
Lada