Question

The
normal boiling point of ethanol is 78c and has an enthaply of
vaporization value of 38.9 kJ/mol. What value must the pressure be
if we want to boil ethanol at 25c in a vacuum distillation?

Change temperature to kelvin

Answer #1

**Solution :**-

Normal boiling point T1 = 78 C + 273 = 351 K

Normal pressure P1 = 1 atm

Final pressure P2 = ?

Final temperature T2 = 25 C +273 = 298 K

Delta H vap = 38.9 kJ/mol * 1000 J /1 kJ = 38900 J/mol

Using the Clausius Clapeyron equation we can find the pressure at which the ethanol will boil at 25 C

Ln [P2/P1] = (delta H vap / R) [(1/T1)-(1/T2)]

Ln[P2/1 atm] = (38900 J/mol / 8.314 J per mol K)*[(1/351K)-(1/298K)]

Ln[P2/1 atm] =-2.37

P2/1 atm = e^(-2.37)

P2/1 atm =0.0935

P2 = 0.0935 * 1atm

P2 = 0.0935 atm

**Therefore the pressure needed is 0.0935 atm**

The normal boiling point of ethanol is 78.3oC. Assuming an
average molar enthalpy of vaporization value of 40.0 kJ/mol in the
temperature interval between 20.0oC and the normal boiling point,
calculate the vapor pressure of ethanol at 30.0oC.

Benzene has a heat of vaporization of 30.72 kj/mol and a normal
boiling point of 80.1 oC. At what temperature
does benzene boil when the external pressure is 490 torr?

Benzene has a heat of vaporization of 30.72 kJ/mol and a normal
boiling point of 80.1 ∘C. At what temperature does benzene boil
when the external pressure is 440 torr ?

12.62
Benzene has a heat of vaporization of 30.72 kJ/mol and a normal
boiling point of 80.1 ∘C.
At what temperature does benzene boil when the external pressure
is 405 torr ?

The normal boiling point of ethanol is 78.3 ∘C, and the heat of
vaporization is ΔHvap = 38.6 kJ/mol.
Part A
What is the boiling point of ethanol in ∘C on top of Pikes Peak
in Colorado, where P = 401 mmHg?
Express your answer with the appropriate units.

the molar heat of vaporization of ethanol is 39.3
kj/mol and the boiling point of ethanol is 78.3 celcius calculate
delta s for the vaporization of 0.60 mol of ethanol

The normal boiling point of liquid ethanol is
351 K. Assuming that its molar heat of
vaporization is constant at 45.1 kJ/mol, the
boiling point of C2H5OH when
the external pressure is 0.602 atm is ? K.

Benzene has a heat of vaporization of 30.72kJmol−1 and a normal
boiling point of 80.1 ∘C.
At what temperature does benzene boil when the external pressure
is 599 mbar ?

Propane has a normal boiling point of -42.0 ∘C and a heat of
vaporization (ΔHvap) of 19.04 kJ/mol. What is the vapor pressure of
propane at 40.0 ∘C

Propane has a normal boiling point of -42.0 ∘C and a heat of
vaporization (ΔHvap) of 19.04 kJ/mol. What is the vapor
pressure of propane at 40.0 ∘C?

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 6 minutes ago

asked 12 minutes ago

asked 22 minutes ago

asked 48 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago