Ask A Scientist© Chemistry Archive

name        Henry
status      other
age         old

Question -  Wich chemical is used to make a pH7 buffer solution?
How much is used to make up 1L? Also the same for pH4?
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Henry
Formulas for the different pH values from 1 to 13 in differences of 0.1
pH units can be found in the Handbook of Chemistry and Physics, published by
the Chemical Rubber Company and other chemical handbooks.

For pH=7.00 the composition of the buffer solution is: 50 ml 0.1 molar
potassium dihydrogen phosphate and 29.1 ml of 0.1 molar NaOH.

For pH= 4.00 the composition of the buffer solution is: 50 ml of 0.1 molar
potassium hydrogen phthalate and 0.1 ml of 0.1 molar NaOH.

Vince Calder
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