To observe an elevation of boiling point is 0.05oC, the amount of a solute (molecular weight = 100) to be added to 100 g of water (Kb - 0.5) is

Elevation of boiling point,∆Tb=w×Kb×1000M×Win gram(Here, w and W- weights of solute and solvent respectively, M = molecular weight of solute and Kb = constant)On substituting values, we get                       0.05=w×0.5×1000100×100 or   w=0.05×100×1000.5×1000= 1 g