The balanced chemical equation for the reaction between diprotic acid and calcium hydroxide is:
H2A + Ca(OH)2 → CaA2 + 2H2O
Where H2A represents the diprotic acid.
From the balanced equation, we can see that 1 mole of diprotic acid reacts with 1 mole of calcium hydroxide.
Let's first calculate the number of moles of calcium hydroxide used:
n(Ca(OH)2) = C x V = 0.1432 M x 21.37 mL / 1000 mL = 0.003057 moles
Since 1 mole of diprotic acid reacts with 1 mole of calcium hydroxide, the number of moles of diprotic acid used is also 0.003057 moles.
The volume of diprotic acid used is given as 10.00 mL, which is equivalent to 0.01 L.
Therefore, the molar concentration of diprotic acid can be calculated as:
Molarity = number of moles / volume in liters
Molarity = 0.003057 moles / 0.01 L = 0.306 M
Therefore, the molar concentration of the diprotic acid is 0.306 M.