Question

Calculate the molarity of a solution of sodium hydroxide, naoh, if 23.64 ml of this solution is needed to neutralize 0.5632 g of potassium hydrogen phthalate, khc8h4o4.

Answer 1

The  molarity  of  NaOH  needed  is  calculated   as  follows
calculate  the  moles  of  KhC8h4O4

that  is  moles  =  mass/molar  mass  of  KhC8h4O4(204.22 g/mol)

=0.5632g /204.22g/mol=  2.76  x10^-3  moles

write the  equation  for  reaction

khc8h4O4  +  NaOH  ---> KNaC8h4O4  +  H2O

from  the  equation  above  the   reacting  ratio   of   KhC8h4O4  to  NaOh  is  1:1  therefore  the  moles  of  Naoh  is  also  2.76  x10^-3  moles

molarity  of NaOh  =  (moles  of  NaOh /  volume ) x  1000

that  is { (2.76  x10^-3) / 23.64}  x100  =0.117 M