Saved Bookmarks
| 1. |
A solution containing 0.2563 g of naphthalene (molecular mass = 128) in 50 g of carbon tetrachloride yields a boling point elevation of 0.201^(@)C while a solution of 0.6216 g of an unknown solute in the same mass of the solvent gives a boiiling point elevation of 0.647^(@)C. Find the molecular mass of unknown solute. |
|
Answer» Solution :We KNOW that `K_(B) = (DeltaT_(b) XX W_(1) xx Mw_(2))/(1000 xx W_(2))` For `C Cl_(4) , K_(b) = (0.201 xx 50 xx 128) /(1000 xx 0.2563) = 5.019` `Mw_(2) = (1000 xx K_(b) xx W_(2)) / ((DeltaT_(b) xx W_(1))` `=(1000 xx 5.019 xx 0.6216) /(0.647 xx 50)` `= 96.44` |
|