Question

Calculate the concentrations of NaOH and maleic acid.

100 mL of 0.1 M NaOH was transferred into a buret. 0.433 g of maleic acid was dissolved in a 100 mL volumetric flask. 25 mL of this solution was transferred into a plastic beaker, and 50 mL of distilled water was added.

6 mL of NaOH was added to get to the first equivalence point (brought pH to 1.99), and a total of 30 mL was added to reach the second point (brought pH to 5.54).

Answer 1

Mdarity of maleic acid = Mass x1000 Molar massx Vol ¡0.433 x1000M -0.0373(M) 116.1 X 100) CHCOOH rag) + 2NaOH(aq) = CHCOONE CHCOOH de + 2H:20 2 mol. ..25 ml of 0.0373(M) Maleic acid = 25%0.0373 mol maleis, 1000 aud 2X25X0.0375 mol NaOH 2X25X0.0373 X100 1000 1000 (M) = 0.0622(M) 1000 x 30 (M) = 0.06.22(M) CHCOONa I mol