For the best system, calculate the ratio of the masses of the buffer components required to make the buffer. express your answer using two significant figures. m(nh3)m(nh4cl) = 0.23

Since the pKb is is 4.75, the pKa is 9.25. Also, in the Henderson Hassalbalch, Molarity and moles are generally interchangeable if its the same solution. pH = pKa + log (NH3/NH4Cl) 9.05 = 9.25 + log (Mole Ratio) -0.2 = log (Mole Ratio) 10^-0.2 = Mole Ratio Mole Ratio = 0.631 Now, that means for every mole of Acid, there are 0.631 moles of base. So we multiply the moles of base by the molar mass of NH3 and we multiply the moles of Acid by the molar mass of NH4Cl. Base: 0.631 mol x 17.0 g/mol = 10.7 g NH3 Acid: 1.00 mol x 53.5 g/mol = 53.5 g NH4Cl Now we just divide them to get the ratio. 10.7 g NH3 / 53.5 g NH4Cl = 0.200

Heptagon is the correct ans