Problem 1.

Derive an expression for the mixing entropy ∆Smix of a ternary system.

Simplify your result, writing it as the total number of particles N times a purely intensive function of the mole fractions of all three components.

Humid air at 70.0 °C and 1.00 atm with 2.00 °C of superheat is fed to a condenser. Gas and liquid streams leave the condenser in equilibrium at 15.0 °C and 1.00 atm.

Use material balances to determine the following quantities for a basis of 100.0 mol of warm, humid air fed to the condenser.

In a power plant based on a simple Rankine cycle, steam enters the turbine at 15 MPa and 900°C. The condenser pressure is 5 kPa. The turbine operates adiabatically and has an isentropic efficiency of 85%, and the pump also operates adiabatically and has an isentropic efficiency of 80%. Determine

1. the work required to pump the water to the boiler in kJ/kg of water flowing, and

2. the enthalpy of the water leaving the pump.

Ethylene glycol at 40 degree C flows along a heated vertical plate L = 0.5 m long and is maintained at a uniform temperature of 80 degree C. Determine the minimum flow velocity below which the effect of free convection on heat transfer becomes more than 5 percent. (For ethylene glycol take Pr = 50.)

Define, describe and explain the following with graphical representations:

(a) Equilibrium

(b) Phase in a material

(c) Degrees of freedom for a material system

(d) Cooling curves; and

(e) A phase diagram

Liquid methanol is fed to a space heater at a rate of 12.0 L/hr and burned with excess air. The product gas is analyzed and the following dry basis mole percentages are determined: CH₃OH: 0.45%, CO₂=9.03%, CO=1.81% (make sure you think about what else needs to be in the product gas).

a) (1 point) Draw and fully label a PFD

b) (2 points) Calculate the fractional conversion of methanol, the percentage excess air fed, and the mole fraction of water in the product gas.

c) (1 point) Suppose the products are released directly into a room. What potential problems do you see and what remedies do you suggest?

• Specific heat of ice: 2.09 J/(g⋅∘C
• Specific heat of liquid water: 4.18 J/(g⋅∘C)
• Enthalpy of fusion: ΔHfus=334J
• Enthalpy of vaporization: ΔHvap=2250 J/g
• How much heat energy, in kilojoules, is required to convert 47.0 g of ice at −−18.0 ∘C∘C to water at 25.0 ∘C?

9.77

Methane is burned with 25% excess air in a continuous adiabatic reactor. The methane enters the reactor at 25 C and 1.10 atm at a rate of 550 L/s, and the entering air is at 150 C and 1.1 atm. Combustion in the reactor is complete, and the reactor effluent gas emerges at 1.05 atm.

a) Calculate the temperature and the degrees of superheat of the reactor effluent. (Consider water to be the only condensable species in the effluent).

b) Suppose only 15% excess air is supplied. Without doing any additional calculations, state how the temperature and degrees of superheat of the reactor effluent would be affected [increase, decrease, remain the same, cannot tell without more information] and explain your reasoning. What risk is involved in lowering the percent excess air?

benzene has commonly been used as an industrial intermediate, but its use has a declined in recent years. Why? What is primarily used for? What has it been replaced by in many synthesis reactions?

77. Calculate Q for a stream with weeds in the channel (n = 0.035). It has an average width of 4.5 feet at gaging station A. Its average depth at the gaging station is 1.5 feet. The gradient of the water surface is 1.7 ft in the vertical over a distance of 1000 ft in the horizontal. Calculate V and then Q.

78. Why is it important to measure soil moisture? Go into the direct and indirect ways soil moisture is critical for human activities, the economy, forecasting applications etc

What role does nucleation and kinetics in general have for making a single crystal silicon wafer? Describe the process to make this, highlighting the steps where kinetics have a strong role.

Consider a gaseous feed, CA0=100, CB0=200, enters a flow reactor at T0=1000 K and ?0= 5 atm. The reaction, ? + ? → 5?, occurs in the reactor. Calculate the XA, XB and CB if the exit
stream leaves at T=400 K and ? = 4 atm. (Assume ideal gas behavior).

Conduct research to find other examples where the exclusion of a species led to dramatic changes in the ecosystem. Explain why this is the case

It is January, and you take off from New York City for a well deserved vacation in the Caribbean. After YOU REACH A CONSTANT CRUISING ALTITUDE of 30,000 ft, would you expect the pressure outside of the plane to...

Methanol is synthesized by the gas phase reaction: Stoichiometric amounts of CO and H2 are mixed in an evacuated vessel (i.e. no methanol is present initially), and the reaction is allowed to come to equilibrium. Calculate the equilibrium mole fraction of methanol under the following conditions. The equilibrium temperature and pressure are 365 K and 1 atm, the mixture behaves as an ideal gas and a more accurate description of the temperature dependence of the equilibrium constant is available where T is in K.

ln K = 21.8158+9,052/(T)-7.663ln(T)+5.4075x10-3 (T)-5.75x10-7 (T2 )-6.75x103 /(T2 )