A solution of malonic acid, H2C3H2O4, was standardized by titration with 0.1000 M NaOH solution. If 21.09 mL of the NaOH solution were required to neutralize completely 12.30 mL of the malonic acid solution, what is the molarity of the malonic acid solution

1000cm³ = 1mL = 1dm³

C₃H₄O₄ + 2NaOH → Na₂C₃H₂O₄ + 2H₂O

0.10M = 1000cm³

x M = 21.09cm³

xM = (21.09 * 0.10) / 1000

x M = 0.002109 moles

From equation of the reaction,

1 mole of C₃H₄O₄ reacts with 2 moles of NaOH

1 mole of C₃H₄O₄ = 2 moles of NaOH

y mole of C₃H₄O₄ = 0.002109 moles of NaOH

y = (0.002109 * 1) / 2

y = 0.0010545 moles

0.0010545 moles is present in 12.30cm³

0.0010545 mole = 12.30cm³

z mole = 1000cm³

z = (0.0010545 * 1000) / 12.30

Z = 0.0857M

The molarity of malonic acid is 0.0857M