Question

Determine The Mole Fraction Of Substances In Solution Containing 36g of water and 46g of glaycerine C3H5(OH)3.

Answer 1

Get first the number of moles (n) of each species. To get the moles, divide the mass by the molar mass. To get the molar mass, get a periodic table and add the individual mass of the elements in the chemical formula.
H2O (water): 2*1 + 1*16 = 18 g/mol
C3H8O3 (glycerine): 3*12 + 8*1 + 3*16 = 92 g/mol
Therefore,
n,H2O = 36 / 18 = 2 mol H2O
n,C3H8O3 = 46 / 92 = 0.5 mol C3H8O3
To get the molar fraction of each, get the total moles, and divide each moles by the total:
Total moles = 2.5 moles
molar fraction, H2O = 2/2.5 = 0.8
molar fraction, C3H8O3 = 0.5/2.5 = 0.2

Hope this helps :3