Non-metal atoms gain an electron, or electrons, from another atom to become >negatively charged ions.
According to Raoult's law the relative lowering of vapour pressure of a solution made by dissolving non volatile solute is equal to the mole fraction of the non volatile solute dissolved.
the relative lowering of vapour pressure is the ratio of lowering of vapour pressure and vapour pressure of pure solvent

Where
xB = mole fraction of solute=?

p = 22.8 torr

mole fraction is ratio of moles of solute and total moles of solute and solvent
moles of solvent = mass / molar mass = 500 /18 = 27.78 moles
putting the values




mass of glucose = moles X molar mass = 1.218 X 180 = 219.24 grams