Vapour pressure of solution of solids in liquids
o
Let p total = Total vapour pressure
p1 = Partial vapour pressures of component 1
p2 = Partial vapour pressures of component 2 x1 = Mole fractions of component 1 . x2 = Mole fractions of component 2
o
o o
Dalton ’ s law of partial pressures states that the total pressure ( ptotal ) of the solution is the sum of the partial pressures of the components of the solution .
Mathematically , P total = P1 + P2 Substituting the values of p1 and p2 we get
o The minimum value of
ptotal is p1 0 and the maximum value is p2 0 , assuming that p1 0 < p2 0 .
o Let y1 = Mole fractions of the component 1
y2 = Mole fractions of the component 2
According to Dalton ’ s law of partial pressures :
P1 = y1 Ptotal
P2 = y2 Ptotal
Vapour pressure of solution of solids in liquids
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Solution of salt , sugar or glucose dissolved in water is solutions of solids in liquids .
Similarly iodine and sulphur dissolved in carbon disulphide are also solutions of solids in liquids