1. the freezing point depression constant of carbon tetrachloride is 30 degrees c/m. the density of carbontetrachloride is 1.584g/cm^3. The normal freezing point of carbon tetrachloride is -23 degrees C.

a. calculate the freezing point of a solution made by mixing 12.28g of solid iodine with 250 ml of carbon tetrachloride. (show all work)

b.calculate the freezing point of a solution made by mixing 12.28g of solid naphthalene (C10H8) with 250 ml of carbon tetrachloride. (show all work)

This question is from the material science class.

Briefly describe

1. Grain refinement

2.Solid-solution formation

3. strain hardening(cold work)

4. Precipitation Strengthening

a) Distinguish between processing of thermoplastics and thermoset polymers to make a final product (the process is not to make the polymer, but to make the final product) and relate this to the microstrucural differences of he polymers.

b)Using the concept of the relation between glass transition temperature and stucture, explain why polyethylene is ductile at room temperature whereas polystyrene is brittle at room temperature.

Please answer both parts

1)A geothermal reservoir in Indonesia has a downhole fluid of water at a temperature of 235°C. The specific enthalpy of the fluid is 2500 kJ/kg, and consists of two phases. What is the quality of the steam?

a) Define the following terms: (i) ferroelectric (ii) piezoelectric

b)Draw perspective and plan views of the unit cell of cubic barium titanate. Label the fractional co-ordinates of the non-equivalent ions and state the co-ordination number of the ions. [6 marks] (ii) Describe, with the aid of appropriate diagrams, the various structural changes which occur as a barium titanate crystal cools from 200°C to -100°C. Specify the temperatures of the relevant phase transitions.

The elementary irreversible gas phase reaction A --> B + C is carried out in a PFR packed with catalyst. Pure A enters the reactor at a volumetric flowrate of 20 dm³ /s at a pressure of 10 atm and 450K.

C_pA=40 J/mol.K H_fA=-70 kJ/mol   (T_R=273 K)

C_pB=25 J/mol.K H_fB=-50 kJ/mol

C_pC=15 J/mol.K H_fC=-40 kJ/mol

k = 0.133 exp ( E/R*[ 1/450 ? 1/T ] ) dm³ kg cat. s with E = 31.4 kJ/mol

a) Plot the conversion and temperature down the plug flow reactor until 80% conversion is achieved.

b) Calculate the amount of catalyst required to achieve 80% conversion.

Explain Step by step how to do the standard design procedure for a heat exchanger and how to critically assess the shortcomings of using a certain method.

What is the maximum concentration of carbon possible in the FCC phase of iron before causing precipitation of either Fe3C or liquid? At what temperature is the carbon solubility in FCC iron a maximum?

This problem is related to bioprocess engineering. There is a problem named 'Lysine project'

There are some conditions for this problem:

•Annual capacity of lysine production: 100,000 ton

(each bioreactor volume < 100 m³)

- Microbial host: Corynebacterium

- Lysine productivity: 2 g lysine l-1 hr-1

- Cell respiration rate q_o2: 20 mmol O2 gDW-1 hr-1

- Cell concentration: 10 gDW l-1

- Dissolved oxygen concentration setting value: 2 mg O2 l-1

- Saturated dissolved oxygen concentration: 8 mg O2 l-1

I solve these tasks from above conditons(Result values should show exact number):

•Sizing of bioreactor

(Diameter, height, baffle etc.)

•Agitator type, agitator size

•Agitator operation condition: rotation speed (rpm)

•Aeration flow rate

What is meant by the term ‘sacrificial anode’? Use diagrams and/or equations to illustrate your answer.

Chemistry 252 has focused on two main topics: the nature of the equilibrium state, and the rates of processes that take place to achieve equilibrium, i.e., chemical kinetics.

Write a paragraph that compares the information content required to describe the equilibrium state with that necessary to describe the rate processes that connect reactants and products.   In your answer, include a discussion of the energy levels, molecular motions, and appropriate length scales of all important species involved in specifying the equilibrium state. Include a similar discussion for any key species that play a role in the reaction rates that establish equilibrium.   Indicate how the properties of these species are incorporated into a theory of reaction rates.

Topics that may be helpful in constructing your answer:

             Potential energy surface

             Reaction coordinate

             Partition functions    

             Transition state

             Saddle point

Your paragraph should be written in acceptable scientific prose. You should use complete sentences, and the logical flow of your arguments should be clear. There is no word limit, but preferably no longer than a page typed.