## Chemistry and Chemical Reactivity (9th Edition)

The molar mass of water: $1.008|_H\times 2+15.999|O=18.015\ g/mol$ The number of mols of water: $270\ g\div18.015\ g/mol=14.988\ mol$ The molar fraction of urea: $1.0/(1.0+14.988)=0.0625$ Molality: $1.0\ mol\ urea/0.27\ kg\ water=3.70\ molal.$