no of moles of acetic acid = molarity * volume in L
                                         Â
= 2*1 = 2moles
no of moles of acetate      Â
= 1*1 = 1 moles
no of moles of
HCl          =
x
PHÂ Â = PKa + log[Acetate]/[Acetic acid]
4.19 = 4.74 + log1-x/2+x
log1-x/2+x  = 4.19-4.74
log1-x/2+x   = -0.55
1-x/2+x     = 10-0.55
1-x/2+x    = 0.2818
1-x        =
0.2818*(2+x)
x         =
0.3404
no of moles of HCl = 0.3404 moles
mass of HCl = no of moles * gram molar mass
                  Â
= 0.3404*36.5Â Â = 12.4246g >>>>>
answer
