Calculate the concentration of disodium phosphate (Na2HPO4) and monosodium phosphate (NaH2PO4) to prepare of 100.0mM buffer at pH 7.50. the pKa of H2PO4= 7.21
pH = pKa + log [Na2HPO4]/[NaH2PO4]
7.5 = 7.21 + log [Na2HPO4]/[NaH2PO4]
log [Na2HPO4]/[NaH2PO4] = 0.29
[Na2HPO4]/[NaH2PO4] = 100.29 = 1.95
[Na2HPO4] = 1.95 * [NaH2PO4]
also, [Na2HPO4] + [NaH2PO4] = 100 mM = 0.1 M
so, 2.95 * [NaH2PO4] = 0.1
[NaH2PO4] = 0.34 M
[Na2HPO4] = 0.66 M
Calculate the concentration of disodium phosphate (Na2HPO4) and monosodium phosphate (NaH2PO4) to prepare of 100.0mM buffer...
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