Question #98e37

1 Answer
Oct 2, 2016

Let the molar mass of the given mono-basic acid of (empirical formula C3H4O3) is m g/mol
If 2.2 g is dissolved in water to produce 1 L solution then the strength of the acid solution will be =2.2g/L=2.2mM

Since the acid given is mono basic one the mole ratio in which the acid and NaOH will react is 1:1.

25 mL 0.5M NaOH 25×0.51000 mol NaOH=0.0125molNaOH

As this 25mL NaOH solution completely neutralizes 1 L acid solution containing 2.2m mol acid we can write

2.2m:0.0125=1:1

m=2.20.0125=176 g/mol

The given empirical formula of acid is C3H4O3

Let its molecular formula be (C3H4O3)n

So by this MF its molar mass becomes

=3×12+4×1+3×16)n=88n g/mol

So

88n=176

n=17688=2

Hence the Molecular formula of the acid is

(C3H4O3)2=C6H8O6