--%>

Problem on heat of sublimation

Using the vapor pressure data provided below, estimate

i) the heat of sublimation of ice,

ii) the heat of vaporization of water,

iii) the heat of fusion of ice and compare your estimate with the published value of 6010 J/moL

iv) the triple point of water (pressure and temperature). Solve the nonlinear.

                                           T(°C)                             Vapor Pressure (mm Hg)
Ice                                       -4                                            3.280
                                            -2                                            3.880
Water                                   +2                                            5.294
                                            +4                                            6.101

E

Expert

Verified

At 1 atm pressure, ice melts at 0°C

density of ice = 920 kg/m3
density of liquid water = 997 kg/m3

Now using the Clapeyron equation

dP/dT = LP/RT2  [ where Vg>>>Vl]

On integration:

Ln[P1/P2] = -L/R[ 1/T1 -1/T2]

Ln(3.880/3.280)= -L/R [ 1/271-1/269]

So Ice  L = ΔH sublimation = - 50911.5 J/mol =-50.9115KJ/mole

Similarly for water L = ΔH vap =- 44929.9 J/Mole =- 44.929 KJ/mole

Now At triple point Ice /Water /Saturate water Vap co-exists Now using the Thermo concept at triple point 

ΔH sublimation = ΔH vap + ?H fusion

Similarly  at triple vap pressure of water = vap pressure of ice

LnP = ln(3.880)-50911.5/8.3145[1/T – 1/271] = ln(5.294)-44929.9/8.3145[1/T-1/275]

So Solving for T we get T =273.1297K

Now Solving for P we get

LnP = ln(3.880)-50911.5/8.3145[1/273.129 – 1/271]
LnP = 1.532014

So P = 3.589546 mmHg

   Related Questions in Chemical Engineering

  • Q : Bsc what is the latent heat of

    what is the latent heat of vaporization for hexane

  • Q : Calculating adiabatic flame temperature

    Calculate the adiabatic flame temperature of acetylenes gas at a pressure of 1 bar under the following conditions. The reactants are initially at 298K. Assume that the acetylene reacts completely to form CO2 and H2O:

    Q : Thermodynamics Please can you look into

    Please can you look into this assignment and let me know if its solve able.

  • Q : Production of ethanol Ethanol (1)

    Ethanol (1) Describe the production of ethanol in Scottish Whisky beverages. Be sure to include a discussion on dangers of impurities (2) Explain the impact of ethanol on the human body (3) List th

  • Q : Problem on flow rate of natural gas

    Natural Gas is flowing through a 10 inch schedule 40 pipe. The gas is at 109°F and 7.3 psig. The outside air temperature is 92°F. If the flow rate of the gas is 8,000 SCFM: What is the flow rate in lb/hr?

  • Q : Draw a flow diagram and annotate the

    Cumene is produced by the vapour phase reaction of benzene with propylene. The fresh feeds have the following compositions: Benzene: 99% w/w benzene, 1% w/w toluene Propylene: 98% v/v propylene,

  • Q : Calculate the pressure Calculate the

    Calculate the pressure at the bottom of a column of Ethanol 100 ft high using a pressure (force) balance in American Engineering Units.

  • Q : How to balance Chemical Reaction

    Consider a chemical reaction: a CH3-CH=CH2 + b NH3 + c O2 → d CH2=CH-C≡N + e H2O 1.  &

  • Q : Problem on Clausius-Clapeyron equation

    The Clausius-Clapeyron equation gives us an expression for dP/dT. Now we will derive an analog to the Clausius-Clapeyron equation by obtaining an expression for dT/dµ when two phases are at equilibrium. For simplicity, let’s derive this fo

  • Q : Problem on ideal gas law A stream of

    A stream of steam at 1 bar and 400 K enters a compressor through a pipe with cross-sectional area of 0.1 m2 at a velocity of 5 m/s. The pressure of the outlet stream is at 5 bar, temperature is at 500 K, and velocity is 1 m/s. Assume the steam can be descri