Question

What is the mole fraction of a mixture containing 18 gram water and 414 ethanol?

Answer 1

Given mass of water = 18 gm

molecular mass of water (H₂O) = 1x2+16 = 18

⇒ no. of moles of water = 18/18 = 1

Given mass of Ethanol = 414 gm

molecular mass of Ethanol(C₂H₅OH) = 46

⇒ No. of moles of Ethanol = 414 / 46 = 9

∴ Mole fraction of water in Solution = 1/(1+9)

Mole fraction of water in Solution = 1/10 = 0.1 {Answer}