At `27^(@)C`, a `5%` solution `("wt."//"vol")` of cane-sugar is isotonic with `8.77 g//litre` of urea solution. Find `m.wt`. of urea, if `m.wt`. of sugar is `342`. Also report the osmotic pressure of solution is `100 mL` each are mixed at `27^(@)C`.

Explanation

For isotonic solutions, having neither dissociation nor association nature of solutes.
`C_(1) = C_(2)`
or `(w_(1))/(m_(1)V_(1)) = (w_(2))/(m_(2)V_(2))`
For sugar, For urea
`(5)/((342 xx 100)/(1000)) = (8.77)/((m xx 1000)/(1000))`
`:. m = (8.77 xx 342)/(5 xx 10) = 59.99`
On mixing `100 mL` of cane sugar with `100 mL` urea solution, the total volume ow contains `200 mL` in which `5 g` cane sugar and `0.877 g` urea is present.
Thus, `pi xx (200)/(1000) = [(5)/(342)+(0.877)/(60)] xx 0.0821 xx 300`
`pi = 3.60 atm`