First answer is 0.123M Second answer is 11.31 I know the answer but I do not kno
ID: 548260 • Letter: F
Question
First answer is 0.123M Second answer is 11.31 I know the answer but I do not know how to get answers. Please show me the procedure. 4. (25 points) Titrations A 34.5 ml sample of the weak acid phenol (HC&H;,O) of unknown concentration is titrated with a 0.100M sodium hydroxide solution. It takes 42.6 ml of NaOH solution to reach the equivalence point of the titration. Calculate the initial concentration of the phenol solution. Calculate the pH of the mixture at the equivalence point of the titration.Explanation / Answer
4) phenol(C6H5OH) + NaOH ---> NaOC6H5 + H2O
No of mol of NaOH reacted = 42.6*0.1/1000 = 0.00426 mol
No of mol of C6H5OH reacted = 0.00426 mol
concentration of C6H5OH reacted = n/V = 0.00426/34.5*100
= 0.0123 M
5) at equivalence point,pH depends upon concentration of salt(NaOC6H5)
concentration of salt = n/v*100 = 0.00426/(42.6+34.5)*1000 = 0.055 M
pH = 7+1/2(pkb + logC)
pkb of phenol = 9.89
pH = 7+1/2(9.89+log0.055) = 11.31
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.