vapour pressure of water at293k is 17.53mm .calculate the vapour pressure of solution at 293k containing 6g of urea in 100g of water?

use roults law.you know the pure vapour pressure of the solvent(17.53mm).,can find out mole fraction of the solute and hence can get the apour pressure of the solute

Dear student,

• Raoult's Law states that for an ideal solution the partial vapor pressure of a component in solution is equal to the mole fraction of that component times its vapor pressure when pure: P_a = X_aP_a^o
  P_a = vapor pressure of the solution
  P_a^o = vapor pressure of pure solvent
  X_a = mole fraction of the solvent
• The fractional vapor pressure lowering is equal to the mole fraction of the solute: X_b = (P_a^o - P_a) ÷ P_a^o
  P_a = vapor pressure of the solution
  P_a^o = vapor pressure of pure solvent
  X_b = mole fraction of the solute
• Fractional vapor pressure lowering can be used to calculate molecular mass (formula weight) of a solute.

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