Calculate the mole fraction of the solute in the following aqueous solutions: 

(a) 0.112 M C₆H₁₂O₆ (d = 1.006 g/mL);

(b) 3.20% ethanol, by volume (d = 0.993 g/mL; pure CH₃CH₂OH, d = 0.789 g/mL).