question_answer

A solution of urea \[(mol.\text{ }mass\text{ }56g\text{ }mo{{l}^{-1}})\] boils at \[100.18{}^\circ \,C\,\,at\]at atmospheric pressure. If \[{{K}_{f}}\] and \[{{K}_{b}}\] for water are 1.86 and 0.512k kg\[mo{{l}^{-1}}\] respectively, the above solution will freeze at:

A) \[-\,6.54{}^\circ C\]                  

B) \[-\,0.654{}^\circ C\]

C) \[6.54{}^\circ C\]                     

D) \[0.654{}^\circ C\]