## Chemistry: The Molecular Science (5th Edition)

$70.0\, mmHg$
Moles of water $n_{w}=\frac{mass\,of\, water}{molar\,mass}$ $=\frac{100\,g}{18.0\,g/mol}=5.56\,mol$ Moles of sucrose $n_{s}=\frac{mass\,of\, sucrose}{molar\,mass\,of\, sucrose}$ $=\frac{50.0\,g}{342\,g/mol}=0.146\,mol$ Mole fraction of water $X_{water}=\frac{n_{w}}{n_{w}+n_{s}}=\frac{5.56}{5.56+0.146}=0.974$ Applying Raoult's law: $P_{water}=(X_{water})(P^{0}_{water})$ $=0.974\times71.88\, mmHg=70.0\, mmHg$