An automobile antifreeze contains equal volumes of ethylene glycol (d=1.114 g/mL and FW = 62.07) and water (d=1.00 g/mL) at 25oC. The solution has a density of 1.06 g/mL. What is the molarity of ethylene glycol in the solution?

1 answer

1.06 g/mL x 1000 = 1060g is mass 1000 mL soln.
This 1000 mL soln consists of 500 mL ethylene glycol and 500 mL H2O(equal volumes of ethylene glycol and H2O).
The mass of 500 mL ethylene glycol is 500 x 1.114 g/mL = 557 grams or 557/62.07 = 8.97 moles ethylene glycol per 1000 mL soln or 8.97 M. Check my thinking. I have assumed that the volume of ethylene glycol and H2O are additive which probably is not exactly true.