Question

If you have 5.0 moles of a monoprotic acid with an unknown concentration, and it requires 35.25 mL of 0.137M NaOH to reach the equivalence point in a titration, what is the concentration of the acid?

A) 0.0347 M
B) 0.344 M
C) 0.687 M
D) 1.375 M

Answer 1

The concentration of the monoprotic acid in a titration can be calculated using the moles of base added and the volume of the acid solution. Without the volume of the acid solution, it's not possible to determine the concentration of the acid. The approximate option is (A).

Step-by-step explanation:

To calculate the concentration of the monoprotic acid in a titration experiment, we use the fact that at the equivalence point, the moles of the acid will equal the moles of the base added.

The moles of NaOH added in the titration is calculated by multiplying the concentration of NaOH by its volume in liters:

moles of NaOH = concentration of NaOH (M) × volume of NaOH (L) = 0.137 M × 0.03525 L = 0.0048275 mol

Since the acid is monoprotic, it donates one proton per molecule, thus we can assume a 1:1 mole ratio between the acid and NaOH.

As we have 5.0 moles of the monoprotic acid in the solution, we can calculate its concentration by dividing the total moles of the acid by the volume of the acid solution in liters.