pH Meter Calibration Help

[Smudger]

I have just acquired a cheap meter,and need some help.
I need to prepare 200ml of pH4 solution. I have Sodium Hydroxide,Reagent-Grade pellets,"Not less than 97% Pure,Mol Wt 40.00".
How many grams of this will make up to 200ml of pH4 ?

 

[Prof_Pixel]

I need to prepare 200ml of pH4 solution. I have Sodium Hydroxide,Reagent-Grade pellets,"Not less than 97% Pure,Mol Wt 40.00".
How many grams of this will make up to 200ml of pH4 ?

Like the old saying goes, "You can't get there from here". A pH of 4 is acidic; there is no way a NaOH solution will be acidic.

Calibrations are usually made with buffer solutions. See http://en.wikipedia.org/wiki/Buffer_solution for more info.

 

[drumlin]

You will need buffer solutions. They can be prepared, but you are MUCH better off looking for a small set of pH 4,7,10 buffers (provided that's the range you're working in).

May the force be with you.

 

[DREW WILEY]

Any lab supply can supply you with buffers solutions. You also need to have some distilled water on hand.