Dry air was suvvessively passed through a solution of `5 g` solute in `80 g` water and then through pure water. The loss in weight of solution was `2.5 g` and that of pure water was `0.04 g`. What is mol.wt. of solute?

Dry air was suvvessively passed through a solution of `5 g` solute in

1.	Dry air was suvvessively passed through a solution of `5 g` solute in `80 g` water and then through pure water. The loss in weight of solution was `2.5 g` and that of pure water was `0.04 g`. What is mol.wt. of solute?
Answer» Loss in weight of solution `prop P_(S)` Loss in weight of solvent `prop P^(@)-P_(S)` `:. (P^(@)-P_(S))/(P_(S))=("Loss in wt. of solvent")/("Loss in wt. of solution") = (0.04)/(2.5)` …(1) Also, `(P^(@)-(P_(S)))/(P_(S)) = (w xx M)/(m xx W)` …(2) `:. (0.04)/(2.5) = (5 xx 18)/(80 xx m)` or `m = 70.31`

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Dry air was suvvessively passed through a solution of `5 g` solute in `80 g` water and then through pure water. The loss in weight of solution was `2.5 g` and that of pure water was `0.04 g`. What is mol.wt. of solute?

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