14. At 40°C, heptane has a vapor pressure of about 92.0 torr and octane has a vapor pressure of about 31.2 torr. Assuming ideal behavior, what is the vapor pressure of a solution that contains twice as many moles of heptane as octane? (A) 61.3 torr (B) 51.5 torr (C) 71.7 torr (D) 82.1 torr (E) none of these