In: Chemistry
540 mL of .14M Formic Acid is combined with 330mL of .10M sodium hydroxide, calculate the pH. Ka = 1.8e-4
no of moles of HCOOH = molarity * volume in L
= 0.14*0.54 = 0.0756moles
no of moles of NaOH = molarity * volume in L
= 0.1*0.33 = 0.033moles
HCOOH(aq) + NaOH(aq) -------------> HCOONa(aq) + H2O(l)
I 0.0756 0.033 0
C -0.033 -0.033 0.033
E 0.0426 0 0.033
Pka = -logka
= -log1.8*10^-4
= 3.7447
PH = Pka + log[HCOONa]/[HCOOH]
= 3.7447 + log0.033/0.0426
= 3.7447 -0.11 = 3.6347 >>>>>answer