Question

How many grams of TAPSO and sodium TAPSO must be added to 1.3 L of water to produce a solution with pH 7.6 and a total solute concentration of 75 mM?

Answer 1

moles of total TAPSO   = 75 x 10^-3 x 1.3

                                   = 0.0975

x (acid) + y (salt) = 0.0975 ---------------------------> 1

pH = pKa + log [salt / acid]

7.6 = 7.6 + log (y / x)

y = x ---------------> 2

x = 0.04875

y = 0.04875

moles of TAPSO = 0.04875

mass of TAPSO   = moles x molar mass

                            = 0.04875 x 259.28

                           = 12.6 g

mass of TAPSO = 12.6 g

moles of sodium TAPSO = 0.04875

mass of sodium TAPSO = 0.04875 x 281

                                       = 13.7 g

mass of sodium TAPSO = 13.7 g