Question

What is the mole of NaCl and H₂O ,cal. The mole fraction of NaCl in 200 g aqueous solution content 10% NaCl if At. Wt. H=1 , O=16 , Na=23, Cl=35.5

Answer 1

200 g NaCl aqueous solution consisting of 20 g NaCl [10% NaCl (=200/10 = 20 g NaCl)] and 180 g H2O.

moles of NaCl = Weight / MW = 20/58.5 = 0.342 mole 

moles of H2O = Weight / MW = 180/18 = 10 moles