The correct option is B 18 M, 54 N
Let the mass of the solution be 100 g.
98% by mass H3PO4 means 98 g of H3PO4 is present in 100 g of the solution.
Number of moles = given massmolar mass=9898=1 mol
Density = massvolume
⇒ volume of the solution = 1001.8 mL
Molarity=moles of solutetotal volume of solution (in mL)×1000=11001.8×1000
Normality = Molarity × n-factor
(n-factor for H3PO4 is 3)
Normality = 54 N