Calculate the ph of the solutions obtained by mixing:

a) 50.0 cm3 of 0.25 m ch3cooh and 62.5 cm3 of 0.20 m nach3coo

b) 40.0 cm3 of 0.5 m nh4oh and60 cm3 of 1.0 m nh4cl

c) v cm3 of 0.1 m nah2po4 and 3v cm3 of 0.1 m na2hpo4 (it is actually v not a typo)

ka (ch3cooh) = 1.73 x 10^-5 ; kb (nh3) = 1.8 x 10^-5 ; ka2 (h3po4) = 6.2 x 10^-8

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation: