The moles of potassium that you would need to prepare 1200 g of 5% potassium sulfate solution is 1.538 moles
calculation
calculate the mass potassium using the below formula
%M/M = mass of the solute(potassium)/mass of the solvent (potassium sulfate solution)
let the mass of potassium be represented by Y
then convert % into fraction = 5/100
5/100 = Y/1200
cross multiplication
100y = 6000
divide both side by 100
Y= 60 g
moles of potassium =mass/molar mass
= 60/39=1.538
