Comform enuntului, doar o parte din masa de NaOH va reactiona cu fenolul, cealalta fiind neutralizata de acid
calculam masa de NaOH din solutie
c/100=md/ms => md=c*ms/100=40*200/100=80g NaOH
94g...............40g
C6H5-OH + NaOH -> C6H5-ONa + H2O
94g..............x=40g
=> 40g NaOH raman nereactionate
40g.......1mol
NaOH + HCl -> NaCl + H2O
40g......1mol
Cm=n/Vs => Vs=n/Cm=1/0,5=2L solutie HCl