InterviewSolution
Saved Bookmarks
| 1. |
At `40^(@)C`, the vapour pressure os water is 55.3 mmHg. Calculate the vapour pressure at the same temperature over 10% aqueous solution of urea `[CO(NH_(2))_(2)]`. |
|
Answer» Correct Answer - 53.48 mm Hg Mass of urea in 100 g of soution = 10 = 90 g `"Mass of water in the soltion"=100-10=90g` `"No. of moles of urea"=((10g))/((60"g mol"^(-1)))=5.0 mol` `"No. of moles of water" ((90g))/((18"g mol"^(-1)))=5.0 mol` `"Mole fraction of water"=((5.0 mol))/((5.0mol)+(0.17 mol))=(5.0)/(5.17)=0.967` `"Vapoure pressure of water over aquious solution "=P_("water")^(@)xxC_("water")=(55.3mm)xx0.967` =53.48 mm Hg. |
|