pH solutions

[lada]

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

[rp]

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

[lada]

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

[kimmy]

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

[lada]

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

[kimmy]

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

[lada]

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