Please explain Ostwald Walker experiment.......
Ostwald-Walker method is used foe measurement of vapor pressure lowering.
Step 1:
A steam of dry air is passed through a preciously weighed bulb containing the solution. The air becomes saturated upto the vapor pressure of the solution. Then the saturated air is recovered from the bulb and again the bulb is weighed.
The loss in mass of solution is proportional to the vapor pressure of the solution.
i.e. Δ W1 α Ps
The saturated air(removed from solution bulb), is next passed through another precariously weighed bulb containing pure solvent. Since the vapor pressure of pure solvent(p0) is greater than ps , air will further take up some more vapors from pure solvent until it is further saturated upto a pressure p0. Then the saturated air is renowed from the bulb and again the bulb is weighed.
Then, the loss in mass of solvent, Δ W1+Δ W2 α p0
Hence (p0 - p0)/p0=(ΔW2)/(ΔW1+ΔW2)= (Loss in mass of the solvent)/(Gain in mass of absorbent tube)