Q3. A solution of sodium cyanate, NaCNO(aq), is prepared at a concentration of 0.20 M. Calculate the equilibrium concentrations of OH (aq), HCNO (aq), CNO (aq), and H30* (aq) and the pH of the solution at 25°C Solution NaCNO(aq) -----------------> Na^+ (aq) + CNO^- (aq) 0.2M                                                     0.2M CNO^- (aq) + H2O(l) -----------> HCNO(aq) + OH^- (aq) I        0.2                                              0                 0 C        - x                                              +x                +x E        0.2-x                                            +x                +x Kb   = Kw/Ka = 1*10^-14/3.5*10^-4   = 2.86*10^-11 Kb     =   [HCNO][OH^-]/[CNO^-] 2.86*10^-11   = x*x/0.2-x 2.86*10^-11*(0.2-x)  = x^2 x   = 2.4*10^-6 [CNO^-]  = x  = 2.4*10^-6M [OH^-]  = x  = 2.4*10^-6M [H3O^+]   = Kw/[OH^-] = 1*10^-14/2.4*10^-6  = 4.16*10^-9M PH   = -log[H3O^+] = -log4.16*10^-9 = 8.38 .