What is the vapor pressure of an aqueous ethylene glycol (C_2H_6O_2) solution th

Question

What is the vapor pressure of an aqueous ethylene glycol (C_2H_6O_2) solution that is 14.8% C_2H_6O_2 by mass? The vapor pressure of pure water at 25 degreeeC is 23.8 torr. a) 3.52 torr b) 22.7 torr c) 1.14 torr d) 20.3 torr 8. A solution contains a mixture of two volatile substances A and B. The mole fraction of substance A is 0.35. At 32 degreeC the vapor pressure of pure A is 87 mmHg and the vapor pressure of pure B is 122 mmHg. What is the total vapor pressure of the solution at this temperature? a) 110 mmHg b) 209 mmHg c) 99.3 mmHg d) 73.2 mmHg

Explanation / Answer

answer : option B) 22.7 torr

glycol mass = 14.8 g

glycol moles = 14.8 / 62 = 0.239 = n1

water moles = 85.2 / = 4.73 = n2

mole fraction of glycol = n1 / n1 + n2 = 0.239 / 0.239 + 4.73 = 0.048

Po - PS / Po = mole fraction

23.8 - Ps / 23.8 = 0.048

Ps = 22.7 torr

8) answer : option A ) 110 mmHg

Psoltion = PAXA + PBXB

= 87 x 0.35 + 122 x 0.65

= 110 mmHg

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.