Question

A solution is prepared by mixing 1.00 g of ethanol ( C2H60 ) with 100.0 gram water to give a final volume of 101 ml. Calculate the mole fraction for solute and solvent, and the molality of ethanol in the solution?

Answer 1

Well, here we use several definitions of concentration...

Explanation:

Molarity=moles of solutevolume of solution

=1.00⋅g46.07⋅g⋅mol−1101.0⋅mL=0.215⋅mol⋅L−1

Molality=moles of solutekilograms of solvent

=1.00⋅g46.07⋅g⋅mol−1100.0⋅g×10−3⋅kg⋅g−1=0.217⋅mol⋅kg−1

Mass percent=mass of solutemass of solution×100%=??

χthe mole fraction of water=nwaterTotal moles in solution

100⋅g18.01⋅g⋅mol−11.00⋅g46.07⋅g⋅mol−1+100⋅g18.01⋅g⋅mol−1...and so χwater≅1.0