Many soft drinks contain phosphate buffers. Calculate the ph of an 8 oz soft drink containing 4.4g of sodium dihydrogen phosphate(120g/mole) and 5.4 g of sodium hydrogen phosphate(142g/mol2

Respuesta :

PHG

Explanation:

H2PO4-= 4.4g x 1mol/120 = 0.037mol 0.037mol/

0.24L = 0.15

HPO4-2 = 5.4g x 1mol/142g =

0.038mol 0.038mol/0.24L =

0.16pH = pKa + log

( [HPO4-2] /[H2PO4-]) pKa = 7.2

pH = pKa + log ( 0.16/ 0.15 )

pH = 7.2