CHEMICAL AND BIO-THERMODYNAMICS Question Papers (Supple, 2008)

SET :1

1. It has been suggested that the kitchen in your house is cooled in the summer by closing the kitchen from the rest of the house and opening the door to the electric refrigerator. Comment on this. State clearly and concisely the basis for your conclusions. [6+10]

2. Steam is flowing through a horizontal, well-insulated 3-in. - ID iron pipe, 1500 ft long. The velocity at the entrance to the pipe, where the steam is dry and saturated at 150 psia, is 100 ft/sec. The steam discharges from the exit of the pipe into an adiabatic reversible turbine which exhausts at 14.7 psia. The steam leaving the turbine is in the dry-saturated condition.
(a) Calculate the horsepower produced by the turbine.
(b) Represent by a sketch on T-S plane the change in the state of the steam as it flows through the pipe and the turbine.
(c) What is the state of the steam entering the turbine? [6+6+4]

3. (a) Write the energy equations applicable to compression processes.
(b) Write a brief note on pumps and ejectors [8+8]

4. The excess Gibbs energy of a particular ternary liquid mixture is represented by the empirical expression, with parameters, A12,A13, andA23 functions of T and P only GE/RT = A12x1x2 + A13x1x3 + A23x2x3 Determine the implied expressions for in γ1 and γ2 and In γ3. [16]

5. Explain in detail vapour/liquid Equilibrium. [16]

6. Discuss in detail about Multireaction stoichiometry [16]

7. (a) Explain the Gaden classification from stoichiometric point of view the product formation in fermentation processes.
(b) The following stoichiometric equation describes penicillin systhesis

1.5Glucose+H2SO4+2NH3 + phenyl acetate! Pencillium G + CO2+8H2O

the theoretical yield of pencillium is 1.2g/(gram of glucose). Find out the molecular weight of pencillium G. [8+8]

8. Assume that experimental measurements for a certain organism have shown that cells can convert two-thirds (wt/wt) of the substrate carbon (alkane or glucose) to biomass.

(a) Calculate the stoichiometric coefficient for the following biological reactions
Hexadecane:C16H34 + aO2 + bNH3 ! c(C4.4H7.3N0.86O1.2) + dH2O + eCO2
Glucose: C6H12O6 + aO2 + bNH3 ! dH2O + eCO2
(b) Calculate the yield coefficients Yx/s (g dw cell/g substrate), Yx/O2 (g dw cell/g
O2) for both reactions. Comment on the differences. [8+8]


SET :2

1. (a) Write about the thermodynamic state and state functions.
(b) Write about the steady - state flow process. [8+8]

2. Write short notes:
(a) Write about condensable-fluid cycle.
(b) Write about simple power-plant cycle.
(c) Write about analysis of the steam-power plant cycle. [4+6+6]

3. Maxwell’s equation can be used to evaluate the latent heat of vaporization of a pure substance. Choose the appropriate equation and explain the method to estimate the latent heat of vaporization as a function of temperature using the vapor pressure data. [16]

4. (a) Define chemical potential and write the general equation for Gibbs energy in terms of temperature pressure and chemical potential.
(b) By definition, the partial molar volume is: Vi= [∂(nV)/∂ni]P,T, nj. What physical interpretation can be given to this equation? [8+8]

5. Discuss in detail about VLE from cubic Equations of state. [16]

6. Write short notes
(a) Duhem’s Theory
(b) Degree of freedom [8+8]

7. (a) Explain the Gaden classification from stoichiometric point of view the product formation in fermentation processes.
(b) The following stoichiometric equation describes penicillin systhesis

1.5Glucose+H2SO4+2NH3 + phenyl acetate! Pencillium G + CO2+8H2O

the theoretical yield of pencillium is 1.2g/(gram of glucose). Find out the molecular weight of pencillium G. [8+8]

8. Discuss in detail that electrons in the organic substrate is transferred to oxygen. [16]

SET :3

1. It has been suggested that the kitchen in your house is cooled in the summer by
closing the kitchen from the rest of the house and opening the door to the electric
refrigerator. Comment on this. State clearly and concisely the basis for your
conclusions. [6+10]

2. Write short notes:
(a) Write about condensable-fluid cycle.
(b) Write about simple power-plant cycle.
(c) Write about analysis of the steam-power plant cycle. [4+6+6]

3. Describe the sequential procedure for estimating thermodynamic properties, viz.,
H and S using a cubic equation of state. [16]

4. (a) Discuss chemical potential as a criterion for phase equilibrium.
(b) Define partial molar properties: internal energy, enthalpy, entropy, Gibbs en-
ergy. [8+8]

5. For a mixture of 20% propane 45% n-butane and 35% n-propane (mole present) at
a pressure of 1 MN/m2, calculate
(a) the bubble point and
(b) the due point. [8+8]
The following are the data on vaporization constant (K) at different temperatures
Component K
380C 650C 930C 970C
Propane 1.2 1.9 2.8 2.9
n-butane 0.43 0.8 1.3 1.35
n-pentane 0.14 0.31 0.55 0.6

6. (a) Describe the effect of temperature on reaction equilibrium constant .
(b) Is the following reaction promising as a method of manufacture for sodium
formate.
NaOH(s) + CO(g) ⇀↽HCOONa (s)
The following are the data on F0 [8+8]

Component F0, keal/g mole
CO(g) -32.808
NaOH(s) -90.60
HCOONa(s) -147.0

7. (a) Explain the Gaden classification from stoichiometric point of view the product
formation in fermentation processes.
(b) The following stoichiometric equation describes penicillin systhesis

1.5Glucose+H2SO4+2NH3 + phenyl acetate! Pencillium G + CO2+8H2O

the theoretical yield of pencillium is 1.2g/(gram of glucose). Find out the molecular weight of pencillium G. [8+8]

8. Discus in detail the heat evolved per equivalent of available electrons transferred to oxygen. [16]

SET :4

1. A gas is confined in a cylinder by a piston, 2 in. in diameter, on which rests a “weight”. The mass of the piston and weight together is 8 lbm. The local acceleration of gravity is 32.00 ft/sec2. Assume standard atmospheric pressure.
(a) What is the force exerted on the gas by the atmosphere, the piston, and the weight in pounds force, assuming no friction between the piston and cylinder?
(b) What is the pressure of the gas in pounds force per square inch?
(c) If the gas in the cylinder is heated, it will expand, pushing the piston and weight upward. Assuming that enough heat is supplied to raise the piston and weight 8 in., calculate the work done by the gas in raising the piston and weight. What is the change in potential energy of the piston and weight? Give your answers in foot-pounds force. [4+4+8]

2. Write short notes:
(a) Explain with a schematic diagram the adsorption refrigeration machine.
(b) Write about liquefaction processes. [8+8]

3. By means of schematic thermodynamic diagrams, briefly describe the solid / liquid/ vapor states of matter and the phase boundaries. [16]

4. Describe and discuss the commonly used models for excess Gibbs energy. [16]

5. Derive the Equation for bubble point. [16]

6. Consider a vessel which initially contains only n0 mol of water vapour .If decomposition occurs according to the reaction.
H2O ! H2 + 1/2O2
Find expression which relate the number of moles and the mole fraction of each chemical species to the reaction co-ordinate ε [16]

7. Discuss in detail about the Thermodynamic principles. [16]

8. Assuming that cells can convert two - thirds (wt/wt) of the substrate carbon (alkane) to biomass, calculate the “stoichiometric” coefficients for hexadecane utilization.
C16H34 + α1O2 + α2NH3 ! β1 (C4.4H7.3N0.86O1.2) + β2CO2 + β3H2Oθ [16]