--%>
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 : Problem on frictional losses A stream

    A stream of propane is throttled from 4.298 bar and 450 K to 0.22 bar. This process is irreversible due to frictional losses at the nozzle. a. In words or equations, why are frictional losses irreversible?

    Q : Materials and energy balance you look

    you look up the specific gravity of 96% H2SO4 and find it is 1.858.calculate the weight

    		•
  • 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

    		•
  • Q : Thermodynamics I) Sulphur dioxide (SO2)

    I) Sulphur dioxide (SO2) with a volumetric flow rate 5000cm3/s at 1 bar and 1000C is mixed with a second SO2 stream flowing at 2500cm3/s at 2 bar and 200C. The process occurs at steady state. You may assume ideal gas behaviour. For SO2 take the heat capacity at constant pressure to be CP/R = 3.267+5

    		•
  • 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 : Problem on laboratory solution You are

    You are asked to make up a laboratory solution of 0.10 molar H2SO4 from concentrated (96%) H2SO4 at 56°F. The barometric pressure reads 750 mmHg. You look up the specific gravity of 96% H2SO4 and find it is listed at 1.858. Calculate: (a) th

    		•
  • Q : Problem on weight fraction A gas

    A gas contains 350 ppm of H2S in CO2 at 72°F and 1.53 atm pressure. If the gas is liquified, what is the weight fraction H2S?

    		•
  • Q : Bsc what is the latent heat of

    what is the latent heat of vaporization for hexane

    		•
  • 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 : I need to solve the material and energy

    I need to solve the material and energy balance for the att.

    		•