1. An aqueous solution of calcium chloride contains 45.0% CaCl2 by mass. It is desired to produce a 12.0% solution by dilution with pure water. Determine the following: a. W/F ratio (mass of water added / mass of feed) b. P/F ratio (mass of product / mass of feed

A solution is prepared by dissolving iodine, I2, in carbon tetrachloride , CCl4, at 25 °C. For a solute of molality 0.100 mol kg−1, calculate the change in the chemical potential of the solvent caused by the solute. (c) change of chemical potential (solvent) = __________ J/mol. 3 sig. fig. R = 8.3145 J/Kmol.

Clay slurry is to be processed to dry clay containing only 2% moisture. The slurry, containing 45 kg clay per 1000 kg slurry is allowed to settle in a thickener where part of the water (free of solids) is allowed to overflow. 3.5 kg of concentrated sludge per 15 kg of slurry leave the thickener and go  through a filter where 99% of the solids in the sludge is collected in the form of a wet filter cake. The wet filter cake weighs 1.5 kg per kg of dry solids in the cake. The wet cake is finally sent to a drier where most of the remaining water is made to evaporate. On a basis of 2000 kg of concentrated sludge. Make a complete material balance for the system.

(b) Given the following fuel composition, dry exhaust gas and refuse analysis. Fuel composition (fraction by mass) C 0.69; O 0.05; H 0.03; N 0.01; H20 0.10; Ash 0.12 Dry exhaust gas analysis (fraction by volume) CO2 0.145; CO 0.021; N2 0.779; O2 0.055 Refuse analysis (fraction by mass) C 0.45; Ash 0.55 On the basis of 1 kg of biofuel combustion process, find: (i) The mass of refuse, per kg of fuel burnt. [Hint: using an ash balance]. (ii) The mass of dry gaseous products, per kg of fuel burnt. [Hint: consider a carbon balance]. (iii) Show that the nitrogen in fuel is negligible and then estimate the mass of dry * air, per kg of fuel burnt. [Hint: consider a nitrogen balance]. With Air: dry-bulb temperature 22.8°C, wet-bulb temperature 15.5°C: Thestandard compositions for (dry) air are 21% oxygen and 79% nitrogen on a mölar. basis. Take the molecular weight of dry air as 29 g/mol. You may assume that the atomic.mass of C, H, O andN are 12, 1, 16 and 14, respectively.

26.20 The data provided in Figure 26.7 are based on the diffusion of O₂ into SiO₂ formed from the oxidation of (100) crystalline silicon at 1000°C. Estimate the diffusion coefficient of O₂ in SiO₂ formed from the oxidation of (111) crystalline silicon at 1000 °C, using the data in the table below, provided by Hess (1990).* Time 1.0 2.0 4.0 7.0 16.0 Measured SiO₂ Film Thickness (um) 0.049 0.078 0.124 0.180 0.298 0.070 0.105 0.154 0.212 0.339 The maximum solubility of O₂ in the SiO₂ is 9.6-10-8 mole 0₂/cm³ solid at 1000°C and 1.0 atm O₂ gas partial pressure. *D.W. Hess, Chem. Eng. Education, 24, 34 (1990).

5. An aqueous solution containing 10 moles percent ammonia is to be separated via continuous flash distillation, if the feed is available at 100 moles per hour and at equilibrium the mole fraction of ammonia in the vapour is 5.6 times that in the liquid. (a) Draw the x-y diagram and hence, determine the composition of the distillate and the bottom products if the feed is 40 percent vaporized. (b) Calculate the molar flow rates of the distillate and the bottom products obtainable.

Determine the number of moles and the mass of barium peroxide, BaO2, needed to produce 1.5 kg of barium oxide, BaO (O2 is the other product.)

The surface of a 2.5 mm thick ammonia (A) (NH3) – water (B) (H2O) solution at 298 K is in contact with an organic liquid. At the interface (the surface in contact with the organic liquid and water), the equilibrium concentration of ammonia in water is kept constant at 3% by weight (aqueous solution density at this first point, 992.5 kg/m3). 2.5 mm away, at the other border of the film, the concentration of ammonia in water is 12% by weight (the density of the aqueous solution at this second point is 962.3 kg/m3). The water and organic phase are insoluble in each other. (MA = 17.03 kg/kgmol, MB = 18 kg/kgmol) (Assume the ammonia-water solution is 100 kg.)(a) Calculate the diffusibility of ammonia in water using the Wilke-Chang correlation. (Water viscosity at 298 K, B = 0.8937 x 10-3 Pa.s)(b) Calculate the steady state NA flux.(c) Calculate and explain the flux NB.

You wash a Coplin jar with soap and water to ensure it is clean before running a TLC. You should take the time to make sure there are no drops of water left inside the jar. (True or False)The solvent that the sample is dissolved in must always be the same as the eluant when running a TLC plate.(True or False)You are preparing to spot a sample of crude benzophenone and pure benzophenone on two separate lanes of a TLC plate to analyze the crude product. You can use the same TLC spotter for both samples.(True or False)After running a TLC plate to compare crude benzophenone and pure benzophenone you determine you need to prepare a new TLC plate and rerun the TLC. You can use the same spotter for the crude benzophenone as you did for the first TLC plate.(True or False)

A mixture is 12.5 weight % propylene (C3H6), 12.5 weight % benzene (C6H6), and 75.0 weight % cumene (C9H12). For the mixture described above, calculate the average molecular weight of the mixture (g/mol).