Page 16 - Analytical Chemistry I E-book

4- Mole fraction (X)

Mole fraction of solute = no. of moles of solute / (moles of solute + moles of
solvent)

Mole fraction of solvent = no. of moles of solvent / (moles of solute + moles of
solvent)

Xsolute + Xsolvent = moles of solute + moles of solvent
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total moles total moles

Xsolute + Xsolvent = moles of solute + moles of solvent
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moles of solute + moles of solvent

Xsolute + Xsolvent = 1

Dilution of solution: one and the same equation is applied in case of dilution with
changing the concentration unit on both sides of equation.

ex. In case of molarity
M1 X V1 = M2 X V2
where M1 and V1 are for the stock
i.e the concentrated solution while M2 and V2 are for the final (diluted) solution.

In case of normality N1 X V1 = N2 X V2