Question

if 5.85 grams of NaCl is dissolved in 90 ml of water. the mole fraction of NaCl is???​

Answer 1

Explanation:

Mass ofNaCl= 5.85gNaCl=5.85g

Mass ofH_2O= 90gH2O=90g

Number of moles ofNaCl= \cfrac {5.85}{58.5}= 0.1NaCl=58.55.85=0.1

Number of moles ofH_2O= \cfrac {90}{18}=5H2O=1890=5

Mole fraction of solute=\cfrac {n_{\text{solute}}}{n_{\text{solute}}+n_{\text{solvent}}}nsolute+nsolventnsolute

Mole fraction=\cfrac {0.1}{5+0.1}5+0.10.1

\Rightarrow X_B=0.0196⇒XB=0.0196