--%>
Assignment Help - homework help

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 : Thermodynamics Please can you look into

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

    		•
  • Q : Problem on steam flow in a pipe A

    A stream of steam at 15 bar and 300 oC is used to produce work using a steam turbine. a. Before the turbine, steam flows in a pipe (4 cm in diameter) at a mass flow rate of 3 g/s. Calculate the mean velocity in the pipe

    		•
  • Q : Problem on empirical van Laar equation

    At atmospheric pressure ethyl acetate and ethyl alcohol form an azeotropic mixture containing 53.9% mole of ethyl acetate and boiling at 71.8°C. a) Estimate the values of A & B in the empirical van Laar equation

    		•
  • 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 : 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 : 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 : Temprature To determine the temperature

    To determine the temperature that occurred in a ?re in a warehouse, the arson investigator noticed that the relief valve on a methane storage tank had popped open at 3000 psig, the rated value. Before the ?re started, the tank was presumably at ambient conditions and the gage read 1950 psig. If

    		•
  • Q : Bsc what is the latent heat of

    what is the latent heat of vaporization for hexane

    		•
  • Q : Problem on heat required for process A

    A steady-state flow process is used to heat methanol in a tank. The incoming stream is at 2 bar and 25 oC and has a flow rate of 5 kg/s. The outgoing stream is at 1 bar, 100 oC. Heating is provided by a heating coil immersed in a tank. Given the

    		•
  • Q : Matlab/Simulink assignment Modeling eye

    Modeling eye movements is commonly performed in the Matlab/Simulink pacakage. Based on the Physiological evidence, oculomotor plants have been designed to simulate various eye movements. Choose two eye movement models, one for saccades and the other for pursuit, and simulate the following amplitudes

    		•