A small diameter tube closed at one end was filled with benzene to within 20 mm from the top of the tube and maintained at 295 K and atm pressure of 100 kPa with a gentle stream of air blowing across the top. After 30 kilo-seconds (30 x 103 s) the liquid level has fallen to 25.8 mm. The vapor pressure of benzene at 295 K is 13.3 kPa. Calculate the diffusivity of benzene in air. Density of benzene = 800 kg/m3. Molecular weight of benzene = 78 kg/kg mol.

200 MMscfd natural gas that contains 20vol% CO2 and no H2S is to be transported 60 miles through pipelines to a natural gas liquefaction plant where gas sweetening and dehydration will take place. Suggest:

Minimum specifications for the gas as it enters the pipeline.

Suitable processing sequence for the field facility.

4-20. One accident mitigation procedure is called emergency material transfer, in which the material is transported away from the accident site before it becomes involved. We plan on mitigating a crude oil tank fire scenario by pumping the tank empty in 1 hr total time. The crude oil storage tank is 30 m in diameter, and the crude oil is typically at a level of 9 m. The transfer will be accomplished by pumping the crude oil through a 200-mm (internal diameter) new commercial steel pipe to another tank 40 m in diameter and 10 m high. The pipeline represents 50 m of equivalent pipe.

a. Estimate the minimum pump size (in HP) required to pump the entire tank empty in 1 hr. Assume a pump efficiency of 80%.

b. If a 100-HP pump (80% efficient) is available, how long will it take to empty the tank?

c. What conclusions can be drawn about the viability of this approach? The density of the crude oil is 928 kg/m3 with a viscosity of 0.004 kg/m s.

8.56. Humid air at 70°C and 1.0 atm with 6°C of superheat is fed to a condenser. Gas and liquid streams leave the condenser in equilibrium at 25°C and 1 atm. (a) Assume a basis of calculation of 100 mol inlet air, draw and label a flowchart (including Q in the labeling), and carry out a degree-of-freedom analysis to verify that all labeled variables can be determined. (b) Write in order the equations you would solve to calculate the mass of water condensed (kg) per cubic meter of air fed to the condenser. Circle the unknown variable for which you would solve each equation. Do not do any of the calculations. (c) Prepare an inlet–outlet enthalpy table, inserting labels for unknown specific enthalpies (H^1, H^2, . . .). Write expressions for the labeled specific enthalpies, substituting values or formulas for heat capacities and latent heats but not calculating the values of the specific enthalpies. Then write an expression for the rate at which heat must be transferred from the unit (kJ per cubic meter of air fed to the condenser). (d) Solve your equations by hand to calculate kg H2O condensed/m3 air fed and kJ transferred/m3 air fed. (e) What cooling rate (kW) would be required to process 250 m3 air fed/h?

What difficulties might be encountered if water were used as the thermometric substance in a liquid-in-glass thermometer?

Consider a CSTR where a simple first-order reaction takes place. The rate constant depends on the reactor temperature and can be given the Arrhenius equation. The reactor contents are cooled by a coolant that flows through a jacket around the reactor. Derive the dynamic model of the CSTR. i.e. the change of concentration of component A and the temperature of the reactor, assuming the flow rate and the inlet conditions are constant. You can use linearization technique for this coupled system.

Derive the transfer function relating changes in the reactor concentration to changes (C) in the coolant temperature (Tc).

Solve for CA, CB, and CC versus τ for the reactions A→B, r1 =k1 A→C, r2 =k2CA in a PFTR and in a CSTR for k1 =2 moles liter1 min1 and k2 =1 min1.

Find τ and SB at 90% conversion in a PFTR and in a CSTR for CAo =4 in the reactions of the previous problem. Which reactor type is better?

c) Why is the FID so successful and widely used in the oil and petrochemical industries? What precautions must be taken?

2. A 1.00 m3 rigid vessel is filled with steam with a quality of 98.0% at 180◦C. Energy is added to the vessel until the pressure reaches 3,000 kPa. Determine the following:

a) The initial pressure in the vessel

b) The mass of water in the vessel

c) The final temperature in the vessel

d) The change in enthalpy

The carboxylate groups in sugammadex are linked to the carbohydrate rings by a four-atom linker chain. Suggest whether a shorter or longer chain would make any difference, and whether there are any advantages in having the linker chain used.

An incompressible, Newtonian fluid is flowing through a vertical circular conduit (a pipe). The flow is laminar.

What is the velocity at the inner wall of the pipe? How do you know?

The pipe has diameter a. The velocity profile in the pipe is v_z = b ­– c r². Please express c in terms of a and b. (You are applying a boundary condition to solve this problem.)

Where in the pipe is the velocity a maximum?

Please express the maximum velocity in terms of a and b.

What is the average velocity in the pipe in terms of a and b?

Express the volumetric flow rate in terms of a and b.

Methane reacts with chlorine to produce methyl chloride and hydrogen chloride. Once formed, the methyl chloride may undergo further chlorination to form methylene chloride, chloroform, and carbon tetrachloride. A methyl chloride production process consists of a reactor, a condenser, a distillation column, and an absorption column. A gas stream containing 80 mole% methane and the balance chlorine is fed to the reactor. In the reactor, a single-pass chlorine conversion of essentially 100% is attained, the mole ratio of methyl chloride to methylene chloride in the product is 5:1, and negligible amounts of chloroform and carbon tetrachloride are formed. The product stream flows to the condenser. Two streams emerge from the condenser: the liquid condensate, which contains essentially all of the methyl chloride and methylene chloride in the reactor effluent, and a gas containing the methane and hydrogen chloride. The condensate goes to the distillation column in which the two component species are separated. The gas leaving the condenser flows to the absorption column where it contacts an aqueous solution. The solution absorbs essentially all of the hydrogen chloride and none of the methane in the feed. The liquid leaving the absorber is pumped elsewhere in the plant for further processing, and the methane is recycled to join the fresh feed to the process (a mixture of methane and chlorine). The combined stream is the feed to the reactor.

Using the information provided do the following

Carefully draw and label the process flow diagram

Using a basis of 100 total moles of methane and chlorine calculate the composition and molar flowrate of all the streams.

Using scaling relations to answer part (c).....what molar flow rates and compositions of the fresh feed and recycle stream are required to achieve a methyl chloride production of 1000kg/h?

A steel pipe (k = 43 W/m K) carries a heat‐transfer fluid and is covered with a 2‐cm layer of calcium silicate insulation (k = 0.029 W/m K) to reduce the heat loss. The inside and outside pipe diameters are 5.25 cm and 6.03cm, respectively. If the inner pipe surface is at 150°C and the exterior surface of the insulation is at 25°C, calculate: (a) The rate of heat loss per unit length of pipe (b) The temperature of the outer piper surfac

1. Which item of volumetric equipment should be use to: a. measure approximately 10mL of solution? b. measure 10.10mL of solution?
2. Why is it necessary to rinse a buret or pipet with the liquid to be measured?
3. Indicate whether the following errors are random or systematic.
a. The graduation mark on a pipet is incorrect by +0.11mL.
b. Three students read a buret and obtain values of 25.10, 25.12, and 25.09ml.
c. The balance is not zeroed and a series of weighings are made with the balance initially at 0.0200 g.