vapor pressure of solution = vapor pressure of water *
molefraction
       Â
517.01Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
= 525.8* mole fraction
mole fraction of water = 517.01/525.8 = 0.983
no of moles of water = W/G.M.Wt = 410/18 = 22.8moles
mole fraction of water = no of moles of water/no of moles of water
+ no of moles of solute
              Â
0.983Â Â Â Â Â Â Â Â Â Â Â Â
= 22.8/22.8+x
               Â
0.983*(22.8+x) = 22.8
                      Â
x = 0.394
no of moles of solute = 0.394 moles
molar mass of solute = 16.636/0.394Â Â = 42.22g/mole