Answer to Question #149999 in Chemistry for Christine Kieth

Question

 What is the concentration of NaOH solution for which 11.25 mL is needed to titrate 1.53 g of benzoic acid?

Answer 1

Mass of Benzoic acid= 1.53g

Molar mass of C₆H₅COOH= (12x6)+5+16+16+1= 110gmol^-1

moles of Benzoic acid= mass/molar mass= 1.53/110=0.014mol

The balanced chemical equation of reaction is

C₆H₅COOH + NaOH ---> C₆H₅COONa + H₂O

1mol of Benzoic acid reacts with 1 mole of NaOH

Therefore, 0.014mol of Benzoic acid will react with 0.014mol of NaOH.

Moles of NaOH= 0.014mol

Volume of NaOH= 11.25ml = 11.25/1000 =0.01125L

Concentration of NaOH (Molarity)= moles of NaOH/ Litres of solution

= 0.014mol/0.01125L

= 1.24moldm^-3

Therefore, the concentration of NaOH is 1.24moldm^-3