Textbook Problem

Isocyanic acid (HNCO) can be prepared by heating sodium cyanate in the presence of solid oxalic acid according to the equation

$2\text{NaOCN}\left(s\right)+{\text{H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\left(s\right)\to 2\text{HNCO}\left(l\right)+{\text{Na}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\left(s\right)$

Upon isolating pure HNCO(l), an aqueous solution of HNCO can be prepared by dissolving the liquid HNCO in water. What is the pH of a l00.-mL solution of HNCO prepared from the reaction of 10.0 g each of NaOCN and H₂C₂O₄, assuming all of the HNCO produced is dissolved in solution? (K_a of HNCO = 1.2 × l0⁻⁴.)