1.2. If there is an electrostatic force, compute the force exactly 3µm above the lithium ion. If there is an electrostatic field, compute the field exactly 3μm above the lithium ion.

2.17.7: Two distillation columns with three components. A pair of distillation columns are being monitored by Beatrix and Enrico. Benzene (B), toluene (T), and xylene (X) are fed to the first distillation column. The overhead product of the first column contains only benzene and toluene. Toluene is fed to the first column at 1020 mol/hr while 74.4% of the benzene fed to the first column ends up in the overhead product. The stream exiting the bottom of the first column has a flow rate of 1590 mol/hr with 28.5 mol % benzene, 23.8 mol% toluene, and the rest xylene. The bottoms product from the first column is fed to a second distillation column. Pure xylene exits the bottom of the second column while the overhead product contains only benzene and toluene. Determine the following three unknowns. Flow rate of xylene exiting the second column = Ex: 515 mol/hr Mole fraction of toluene exiting the second column = Ex: 0.582 Flow rate of benzene exiting the overhead product of the first column = Ex: 1.50E mol/hr

A feed mixture consisting of 35 mol% ethanol, 27 mol% n-propanol, 25 mol% methanol and 13 mol% n-butanol is fed to a distillation column. The molar flow rate of the feed is 2500 kmol/h. Methanol is the most volatile component followed by ethanol and n-propanol, while n-butanol is the least volatile component. 99.7 mol% recovery of methanol in the distillate and a methanol mole fraction of 0.99are desired. Determine the molar flow rate of ethanol in Distillate in kmol/h

2.17.8: Making orange juice concentrate. Maximus and Theodora are optimizing a steady state processing making orange juice concentrate. A stream of oranges (0) and a stream of water (W, H₂O) enter a juicing machine. The exit stream from the juicing machine contains 55.8 kg/hr orange juice (OJ, MW = 108), 21.3 kg/hr pulp solids (PS), and 43.5 kg/hr water. The exit stream from the juicing machine enters a filter. The filter removes all of the pulp solids and 20.2% of the water entering the filter as one exiting stream. The other stream exiting the filter contains water and orange juice. The water/orange juice mixture is finally sent to an evaporator to produce a concentrate stream (80.1 wt% orange juice and the balance water) and a stream of pure water. The pure water is recycled, mixed with a fresh stream of pure water, and fed into the juicing machine. Determine the following three unknowns. Mole fraction of orange juice in the concentrate stream =Ex: 0.309 Mass flow rate of water entering the evaporator =Ex: 30.9 kg/hr Mass flow rate of water entering the overall system =Ex: 16.8 kg/hr

2.17.9: Preheater and distillation column. A preheater and distillation column are maintained by engineers Marcella and Julius. A stream of pure acetone (A, C3H6O) and a stream containing acetone, ethanol (E, C2H5OH), and butanol (B, C4H, OH)entering the preheater. One stream exits the preheater containing 144 mol/min butanol, some acetone,and some ethanol; the mole fractions of butanol and ethanol are 0.209 and 0.412, respectively. The stream of pure acetone entering the preheater is 2.42 times larger than the component flow rate of acetone in the other stream entering the preheater. The stream exiting the preheater enters a distillation column, and all of the entering butanol exits in the bottom product stream. The recoveries in the overhead product, which is defined and the ratio of component flow rate exiting to component flow rate entering the distillation column, of acetone and ethanol are 83.1% and 59.2%, respectively. Determine the following three unknowns. Mass fraction of apple in the solid waste =Ex: 0.632 Total flow rate of the concentrate =Ex: 8.82kg/min Flow rate of pure water entering the overall system =Ex: 8.95kg/min

The response of the liquid level in a tank is given by the first-order differential equation: A \frac{d h(t)}{d t}=q_{0}(t) where h(t) is the level in the tank in m, gdt) is the flow of the liquid into the tank in m/s, and A =0.5 m is the constant area of the tank in m2. \text { Obtain the transfer function for the tank, } G(s)=\frac{H(s)}{Q_{0}(s)} Assume that initially the valve of the inlet stream was completely closed and the level in thetank was h(0) = 0.25 m. At t = 0, the valve was opened, and the flowrate was maintained atgo(0) = 0.25 m/min. Knowing that the height of the tank is 3.5 m, after which the tank willoverflow. Determine the time needed to fill up the tank. O Simulate and plot the responses obtained in parts (b) and (c). \text { Obtain the response of the level to a unit step in flow, } q_{o}(t)=u(t) .

A saturated liquid feed of 1000 kmol/h consists of 25 mol% propane, 35 mol% n-butaneand 40 mol% n-hexane. A distillate recovery of 99 mol% n-butane and bottoms recovery of 98 mol% n-hexane isdesired. \alpha_{\text {hexane-butane }}=0.2 Constant molar overflow (CMO) is valid. Reflux is returned as a saturated liquid. Thecolumn has a partial reboiler and a total condenser. \text { Using Gilliland correlation, calculate the total number of stages if } R=1.025 \times R_{\min -} \text { The average relative volatility is } \alpha_{\text {propane }-\text { butane }}=2.04 \alpha_{\text {butane }-\text { butane }}=1.00 \mathrm{and}

3. In a shell-and-tube heat exchanger under design condition, the cooling water gets heated from 30°C to 45°C while the process stream is cooled from 100°C to 60°C. Due to fouling only in the process side, the mass flowrate of water has to be increased to 160% of the design flow to maintain the process side outlet temperature at its design value with the same design flowrate of the process stream. Express the fouling heat transfer coefficient (hr.), which is the inverse of the fouling heat transfer resistance, as a multiple of process side heat transfer coefficient (ho). Assume that under design condition, there is no fouling. Also assume that all the resistance to heat transfer is on the process side.

A saturated vapour feed of 2250 kmol/h consists of 50 mol% methane, 30 mol%propane and 20 mol% n-butane. A distillate recovery of 99 mol% propane and bottoms recovery of 97.5 mol% n-butane is desired. \text { The average relative volatility is } \alpha_{\text {methane-propane }}=9.92 x_{\text {propane-propane }}=\text { and } \alpha_{\text {butane-propane }}=0.49 Constant molar overflow (CMO) is valid. Reflux is returned as a saturated liquid. Thecolumn has a partial reboiler and a total condenser. \text { Calculate the value of } \phi You must state the answer in 4 decimal places.

7) 5 points. Reactants plus solvent enter an adiabatic reactor at 300 K. If the reactants react completely the outlet temperature is 700 K. However, for safety reasons, the outlet temperature must be kept below 500 K. Which of the following steps can reduce the outlet temperature but still allow complete conversion? A. Decrease the amount of solvent fed B. Use a solvent with a lower heat capacity C. Use a stoichiometric excess of one of the reactants D. All of these E. None of these

Engineers Sophia and Giles are modifying a process to make concentrated apple cider starting from a slurry - a slurry is a mixture of solids in a liquid that can normally be pumped. A slurry made with apple shaving a mass fraction of 0.422 and the balance water is fed to a juicer at a rate of 26.2 kg/min. Seventy percent of the apples entering the juicer leave as part of the solid waste stream (containing apples and water). The primary product from the juicer is cider (35.3 wt% apples and 64.7 wt% water). The cider is sent to an evaporator where concentrate - apple concentration increases to 51.5 wt% - is produced along with a stream of pure water that is recycled. The pure water stream leaving the evaporator is mixed with fresh water entering the process. The combined water stream mixes with pristine apples entering the process to create the slurry. Determine the following three unknowns. Mass fraction of apple in the solid waste = Ex: 0.632 Total flow rate of the concentrate = Ex: 8.82 kg/min Flow rate of pure water entering the overall system = Ex: 8.95kg/min