Question

How many liters of 0.200 M sodium hydroxide do you need to titrate 0.400 L of a 0.100 M diprotic acid to the equivalence point? 0.400 L NaOH

A. 0.200 L NaOH

B. 0.300 L NaOH

C. 0.400 L NaOH

D. 0.500 L NaOH

E. 0.800 L NaOH

Answer 1

Given the volume of the diprotic acid, V = 0.400 L

Concentration of the diprotic acid, M = 0.100 M

Hence moles of the diprotic acid = MxV = 0.100M x 0.400 L = 0.0400 L

Since it is a diprotic acid it will require the base equals to double the moles of the diprotic acid taken.

Hence moles of base(NaOH) required = 2 x 0.0400 L = 0.08 mol

Given the concentration of NaOH, M = 0.200M

Let the volume of NaOH added ve 'V' L

Hence moles of NaOH added = MxV = 0.200xV mol

Now 0.200xV mol = 0.08 mol

=> V = 0.08 / 0.200 = 0.400 L NaOH

Hence (c) is the correct answer