HSC 2001 Q23 help needed. (1 Viewer)

[Shoom]

http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2001exams/pdf_doc/chemistr_01.pdf

Q23b

 

[brenton1987]

A household cleaning agent contains a weak base of general formula NaX.
1.00 g of this compound was dissolved in 100.0 mL of water. A 20.0 mL sample of the solution was titrated with 0.1000 mol L^–1 hydrochloric acid and required 24.4 mL of the acid for neutralisation.
What is the molar mass of this base?

NaX + HCl --> NaCl + HX

V_HCl = 0.0244 L
C_HCl = 0.1000 mol L^–1
n_HCl = 0.0024 mol

n_NaX = 0.0122 mol
F_NaX = 81.97 g mol^-1
F_X = 58.98 g mol^-1
X = CH₃COO^-

NaCH₃COO + HCl --> NaCl + CH₃COOH