--%>
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 : 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 : I need to solve the material and energy

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

    		•
  • Q : Problem on heat of sublimation Using

    Using the vapor pressure data provided below, estimatei) 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/moLiv) the triple point of wate

    		•
  • 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 : 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 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

    		•
  • Q : Estimating solubility of oxygen in water

    The Henry's law constant for oxygen in water is as follows: Temperature, °C                     0              &nbs

    		•
  • Q : Bsc what is the latent heat of

    what is the latent heat of vaporization for hexane

    		•
  • Q : Rate of flow of nitrogen The feed to an

    The feed to an ammonia synthesis reactor contain 25 mole% nitrogen and the balance hydrogen. The flow rate of the stream is 3000 kg/hr. Calculate the rate of flow of nitrogen into the reactor in kg/hr. (Hint: First calculate the average molecular weight of the mixture).

    		•
  • 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

    		•