Question

Problem Set 14 CHEM 1252 November 4, 2019 4. At 25 °C, K= 1.0 x 10-14, while at 0 °C, K= 1.2 x 10-15 (a) Explain whether water becomes a stronger or weaker acid as temperature decreases. (b) Write the equilibrium constant expression for the ionization of water to hydronium ion and hydroxide and calculate the concentrations of [H3O*] and [OH in pure water at 0 °C. (c) An aqueous solution at 25 °C has [OH-] = 2.5 x 10-11 M. Is this solution acidic, basic, or neutral? Calculate [H*] for this solution.

Help please and show all work!

Answer 1

Pure watr is always nutral lbecause in eah case But as tamperature decreasos, the 11 degree of onisation of watr decreases ana hene te Value of Kw decreases At eauilibniuu, 2H20 Hs OH LHJLOH Lt20 2 Kddiesocialion Constant of H0 KW Kw=Ionie product of 20=LH3Lon] OY K KLH202 Lt0]= fure wal Amolaru55.55 2 or Kw=Kx (55.55)

At o'c, uw = CH301LOH CH30= LOH] = K = 2X1015 2 * 1015 3.46410M) at 25c 2.5 x 1 LOH = 2.5 x ID M) |x ו%, LOH - -logLH=-og (4xi6) As pH at 25c, the soluhon is audie 4*10 (M) CH+ 2.X1 pH log (4x1D