Chromatography Forum

Posted: **Thu Dec 04, 2008 3:57 am**

Hi

can anyone please tell me how to measure the pH of a compound which is in solid state. I know its a stupid question to ask

but i need some quick response on this.

thanx in advance.

Prashant

Posted: **Thu Dec 04, 2008 5:02 am**

I was really tempted to say to use a "solid state pH sensor" but I won't...

How about dissolving your compound in water and measuring the pH? If this is not a possibility then you will have to justify your answer starting with what dissociation constant is etc...

Posted: **Thu Dec 04, 2008 7:04 am**

pH is a measure of the concentration of H3O+, this is probably VERY low in a dry solid.

Peter

Posted: **Tue Dec 16, 2008 12:24 am**

Hi 2 all

I agree tht if the compound is soluble in water v can measure its pH by dissolving it in water but

- how much amount of sample compound should be dissolved in distilled water

- should the complete compound added must get dissolved in water

- can v use any other organic liquid (which is miscible in water) in proportion with water in order 2 completely dissolve the compound

- if still the compound is largely insoluble then how can v measure its pH

-what if i dont know the dissociation constant of compound.

-if i know the dissociation constant then i should use the following formula
pKa=pH-log [X-]/[HX] but i should know hw the compound is getting dissociated , m i right

Chromatography Forum

pH of compound in solid state

pH of compound in solid state