Define sedimentation process and explain the differences between Type 1, Type 2, Type 3 and Type 4 solids. Draw a rectangular sedimentation tank showing the four zones with a detailed explanation of each zone.

Physical Chemistry
Colligative Properties of Non–Electrolytes

1. A mixture which contains 0.550 g of camphor and 0.045 g of an organic solute freezes at 157.0 °C. The
solute contains 93.46 % of C and 6.54% of H by weight. What is the molecular formula of the compound?

2.An aqueous solution contains 20 g of glucose per liter. Assuming the solution to be ideal, calculate the
osmotic pressure at 25°C.

Physical Chemistry

1.At 50°C the vapor pressure of ethyl alcohol is 219.9 mm Hg. If 6 g of a nonvolatile solute of molecular
weight 120 are dissolved in 150 g of water and ethyl alcohol, what will be the relative vapor pressure
lowerings in the two solvents?

2.A solution composed of 10 g of a nonvolatile organic solute in 100 g of diethyl ether has a vapor pressure
of 426.0 mm at 20 °C. If the vapor pressure of the pure ether is 442.2 mm at the same temperature,
what is the molecular weight of the solute?

For a health and safety topic (or industry) of your choice search a range of sources of information. For each source consider the accuracy, relevance, credibility, reliability of the information. Consider a wide range of sources, including enforcing authorities, specialist information providers, trade unions, special interest groups and charities etc.

Outline the importance of accuracy of the information for health and safety professionals.

1. Steam undergoes a state change from 450°C and 3.5 MPa to 150°C and 0.3 MPa.

Determine ΔH and ΔS using the following:

a. Steam table data

b. Ideal gas assumptions (be sure to use the ideal gas heat capacity for water).

(ANS: 0.0717 kJ/kg-K; -576.8 kJ/kg; 0.143 kJ/kg-K; -555.71 kJ/kg)

A solution containing 35% by mass of Glauber salt, Na2SO4 is cooled down from 323 K to 298 K in a Swenson-Walker crystalliser to form crystals of Na2SO4•10H2O. The solubility of Na2SO4at 298 K is 13.9 kg/100 kg of water, and the required product rate of crystals is 0.1 kg/s. The molecular mass of the anhydrous and hydrated salt is 142 kg/kmol and 322 kg/kmol, respectively. The mean heat capacity Cp of the solution is 2 kJ/(kg K), and the heat of crystallisation is 150 kJ/kg. The cooling water enters and leaves at 285 K and 293 K, respectively, and the overall coefficient of heat transfer is 125 W/m2 K. Assume counter- current flow and that 3% of the initial solution is evaporated.

(i) State the general equation for the calculation of the crystal yield and define the variables used.

(ii) Calculate the crystal yield.
(iii) Calculate the required feed to produce 0.1 kg/s of crystals. (iv) Calculate the heat required to cool the solution.

(v) Calculate the heat of crystallisation and the total heat required. (vi) Calculate the required heat transfer area.

Define reflux ratio and explain its importance in distillation process. (4)

4.2. Explain how the reflux ratio affects number of stages in the distillation column. (4)

4.3. State six conditions of the nature of feed for fixed reflux ratio. (6)

4.4. List six scenarios when liquid-liquid extraction is preferred over distillation. (6)

What are the different types of drug carrying vehicles used for delivering drug in Nanotechnology. Describe briefly about Core-Shell Nanostructures?

1- a) Determine the expansion work performed when 10.0 g of hydrogen is burned at 1.01 bar and 2800 ° C.
b) Explain what the effect would be on the expansion work if one were to count at 1 bar and 25 ° C instead? Don't forget to justify your answer!

From a control process, what is the effect of an overshoot in products composition in a distillation column?

can it be concluded that it is a consequence of an overshoot in temperature inside the column?

1. In carbonitriding of an iron-carbon alloy (steel) initially containing 0.05 wt% C and no nitrogen is subjected to carbonitriding at an elevated temperature and in an atmosphere that gives a surface carbon concentration constant at 0.5 wt% and surface nitrogen concentration constant 0.2 wt%. Find the ratio of the diffusion coefficients ‘C in steel’/‘N in steel’ if after 36 h the concentration of carbon at a position 0.4 mm below the surface is 0.35 wt%, and the concentration of nitrogen at the same depth is 0.10 wt%.

2. Using your knowledge on diffusion mechanisms in solids, would you expect the ratio ‘C in steel’/‘N in steel’ you found in (1) ? (Would you expect DC in steel or DN in steel to be larger?) 3. Sketch expected trends for: a) the concentration of carbon vs depth and the concentration of nitrogen vs depth (on the same graph), b) overall density vs depth, c) the number of substitutional vacancies vs depth.

4. What is the temperature in (1)? Qd for C in steel is 148 J/mol and Do = 2.3 x 10-5 m2 /s 5. In cyaniding, another case-hardening process, carbon source is NaCN. The part to be hardened is heated above 850 C is immersed in a bath of aqueous NaCN. The process produces more efficient diffusion of carbon in just 20-30 min. In comparison to carburization - which takes hours for depositing same amount of carbon at the same depths – cyaniding seems more cost-effective. However, it is not widely used, why? 6. Write down two applications of case-hardening

A Carnot heat engine operates between temperature levels of 600 K and 300 K with 8 MW heat transferred in the boiler. It drives a compressor, which compresses steam from 200 kPa, 200°C to 1 MPa, 500°C. If mass flow rate of the steam is 5 kg/s. determine the following:

(a) The power output of the heat engine (kW).

(b) The power input of the compressor (kW).

(c) The efficiency of the compressor.

A centrifugal pump is to be used to pump water from a lake to a storage tank which is 165 feet above the surface of the lake. The pumping rate is to be 10 - 35 gal/min at a water temperature of 43°F. The water is used for drinking but will have to undergo filtration and chlorine treatment because there is sediment in the lake. The pump on hand can develop a discharge pressure of 60.0 psig pumping at a rate of 40.0 gal/min through a 2 inch schedule 40 pipe. a) How much power does the pump develop? b) Is it sufficient for the task? Why or why not? c) Is the pipe chosen thick enough?