Question

A curious CHE 1131 student purchased a can of soda water from the cafeteria. Upon opening the can and taking a sip, student noticed a tart taste indicating an acidic solution. The content of the soda water revealed it contained only water and carbonation. If the pressure in the can is 2.5 atom, find the pH of this solution. (pKa1=6.35 and pKa2=10.33)

Answer 1

The soda water contain water and carbonation, meam Carbonic acid (H2CO3), which is a di bootic acid. so it will be disociated as, H₂CO₃ Ht + HCO ka, Hcos = H+ + CO2 -> Kaz LK - [H+][ HC, . . [H2003] [#4][10) - © Eleminating [hce] foom equation Dl@, . [+zlog] kan [H] [coz - [ht] kan Kar = 14 THCO )

[41] = kan.kay. [45605] As, FC032.J= [HCO3), both concenkation are equal, .: [H]? = Karikaz [Hot] = √kan. Kar = (kay kan) 2 - log [t] = (-logkay-logkan) [Taking logo / r Taking

..pH = 2 (ekap + Pray) IAs log kanapkan &-log, kay= pkai Given, bka, = 6.35 Play = 10.33 $H 6.35+10.33 2 = 8.34 . ÞH 7 the solution is 8.34,