Van't Hoff factor of 85% dissociated Sodium phosphate solution is

They all are classified as ‘A3B’ type(uni-trivalent) electrolytes…..A3B ⇌3A++B3- ; n=4Examples….M3PO4                     Van't Hoff factor, i = 1-α+nα ;    when n= 4                    Van't Hoff factor, i = 1+3α ; n=4….for AB3 type(tri-univalent) electrolytes…...AB3 ⇌A3++3B- ; n=4Examples…..AlF3, Al(NO3)3α= Degree of ionization  (or) dissociation ;Ex ; For 5% ionized electrolyte  α=5100= 0.05 ;0.1, 0.15, 0.2, 0.25, 0.3…..for 10%, 15%, 20%, 25%, 30% ionized electrolyteα for x% electrolyte = x100; For AB3 or A3B type : i= 1+3α ;i= a) 1.15….5% ionized  b) i= 1.3…..10% ionized c) i=1.45….15% ionized d) i= 1.6…..20% ionized…..Hint: For every 5% increase in ionization i.e for every 0.05 units increase in 'α' value ‘i’ increases by 0.15 units ;