Question

Calculate the volume of 2M of KOH solution that would be required to completely extract the benzoic acid from a mixture containing 2.44g of bezonic acid and 2.040 g of acentanilide MW of KOH= 56 g/mol Benzoic Acid= 122 g/mol

Answer 1

For the complete extraction of the benzoic acid, the numer of moles of the acid and the base must be the same.

So, first we are going to calculete the moles of the bonzoic acid:

We have our equation

n = m/mw

then n (benzoic acid) = (2.040g) / (122 g/mol)

n _{(benzoic acid)} = 0.0167 mol of benzoic acid

then n _{(benzoi acid)} = n _(KOH) (this because they both have the factor of H⁺ and OH^- = 1)

The volumen of the KOH we need depends on the equiatin of molarity

M = n /V so V_KOH= n / M

Then V _(KOH)= (0.0167 mol) / (2M) V _(KOH) = 0.0835 L

We need 0.083 L of KOH 2 M to completely extract de benzoic acid from the mixture.