Saved Bookmarks
| 1. |
Calculate the mass of urea (NH_(2)CONH_(2)) required in making 2.5 kg of 0.25 molal aqueous solution. |
|
Answer» Solution :0.25 molal aqueous solution of UREA means that Moles of urea = 0.25 mole.`""` MASS of solvent (water) = 1 kg = 1000 g `"Molar mass of urea "(NH_(2)CONH_(2))=14+2+12+16+14+2="60 g mol"^(-1)` `therefore"0.25 mole of urea "="0.25 mole "xx"60 g mol"^(-1)=15g` THUS, 1.015 kg of solution contain urea = 15 g `therefore"2.5 kg of solution will require urea "=(15 g)/(1.015 kg)xx2.5kg=37g.` |
|