Set No. Code No. 220805 II-B.Tech. II-Semester Examinations April/May, 2003
1
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MATERIAL SCIENCE FOR CHEMICAL ENGINEERS (Chemical Engineering) Time: 3 hours Max. Marks: 80 Answer and Five question All questions carry equal marks ---
How Engineering materials are classified on the basis of chemical nature and atomic structure. Give characteristic properties, application and examples under each category.
2. a)
Explain electropositive and electronegative elements on the basis of Periodic table. With regard to electron configuration, what do all elements in Group VIIA of the periodic table have in common?
b)
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1.
Explain what types of bonding would be expected for each of the following materials: brass (a Copper-Zinc alloy), rubber, barium sulfide, solid xenon, bronze, nylone and aluminium phosphide?
4. a) b)
Explain a single component system phase diagram with an example. Discuss the phase rule with reference to ‘two components’ system forming ‘Eutectic’?
5. a)
Define Creep. Draw the creep curve under constant –load test and constant stress test and indicate all the regions. Describe the mechanism of creep that becomes important as the temperature of deformation is progressively increased.
b)
The pilling – Bed-worth Ratios of some oxides are given below K2 O = 0.41 Al2 O3 = 1.38 Cr2 O3 = 2.03 Discuss the nature of the oxide layers that are formed on the metal surface based on the ratios of the above oxides. Calculate the Pilling Bed-worth ratio for Cao The density of Cao and Ca are 4030 -3 and 1550 Kg M respectively.
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6. a)
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3.
b)
Enumerate the developments that have taken place in the field of superconductors.
8.
Explain the characteristics of soft and hard magnetic materials with suitable examples.
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7.
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Set No. Code No. 220805 II-B.Tech. II-Semester Examinations April/May, 2003
2
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MATERIAL SCIENCE FOR CHEMICAL ENGINEERS (Chemical Engineering) Time: 3 hours Max. Marks: 80 Answer and Five question All questions carry equal marks
What are advanced materials? How advanced materials are developed through combination of conventional engineering materials?
2.
Give the electronic configurations for the following ions: Fe2+, Fe3+, Cu+, Ba2+, Br-, S2-.
3. a) b)
Write the coordinates of atom positions in cubic diamond and ZnS. Calculate the effective number of atoms in the HCP unit cell. Describe the basis for generating the HCP structure starting from the hexagonal space lattice.
4. a) b)
Explain a binary phase diagram with aid of an example. Write short notes on phase diagram of Cu – Ni system.
5.
Discuss the role of (a) grain boundaries (b)precipitate particles, in strengthening crystalline materials against yield at low as well as high temperatures of deformation.
6. a) b) c)
Define the parabolic law of oxidation What are the common alloying elements added to steel for improving oxidation Briefly discuss about the oxidation resistant materials.
7.
Discuss the various possible potential applications of super-conducting materials
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1.
Deduce the net magnetic moment of Iron, Cobalt and Nickel from the electronic configuration of the atoms.
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8.
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Set No. Code No. 220805 II-B.Tech. II-Semester Examinations April/May, 2003
3
b)
2.
How structure of materials are classified based on scale level? How do these influence the properties of the materials? Briefly state methods used to study structures of a material, important information obtained and their influence on the properties of the materials.
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1. a)
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MATERIAL SCIENCE FOR CHEMICAL ENGINEERS (Chemical Engineering) Time: 3 hours Max. Marks: 80 Answer and Five question All questions carry equal marks ---
How will you explain the formation of covalent bonds between neutral atoms? Account for the fact that inert gas elements do not usually form chemical bonds.
3. a) Calculate the packing efficiency of (I) closed packed structures (FCC and HCP), (ii) monoatomic BCC and SC crystals. b) Find the diameter of the largest atom that would fit an interstitial void in FCC nickel without distortion. State the applications and limitations of phase rule? What is eutectic point? Explain its significance giving an example.
5.
What is the effect of the following operations on the microstructure and mechanical properties of a ductile single-phase alloy initially in the cast and annealed condition? (a)Increasing amount of cold work.
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4. a) b)
(b)Annealing at successively higher temperatures after cold-work. Define Corrosion, give the most common example of Corrosion, What is an electrode potential What is a Galvanic Cell. Name the different types of Galvanic cells. Explain the process taking place in a Daniel Cell
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6. a) b)
Explain the energy gap theory in solids. What is forbidden gap, explain.
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8.
Does a large magnetic moment per atom mean a high Curie temperature? Explain.
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Set No. Code No. 220805 II-B.Tech. II-Semester Examinations April/May, 2003
4
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MATERIAL SCIENCE FOR CHEMICAL ENGINEERS (Chemical Engineering) Time: 3 hours Max. Marks: 80 Answer and Five question All questions carry equal marks ---
What is the difference between a crystal structure and a crystal system? How many types of crystal systems are possible? Describe each crystal system in terms of its unit cell parameters. What is the primitive unit cell?
2. a)
How would you explain that H2O is a liquid while H2S is a gas at ordinary temperature, although the molecular weight of H2O is lower than that of H2S. In what respect the vanderWaals bonds resemble the metallic bonds?
b) 3. a) b)
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1. a) b)
What is the difference in the stacking sequence of close packed layers in FCC and HCP structures? Why do HCP metals, in general exhibit poor ductility as compared to FCC and HCP structures? What is eutectic system? Explain with an example. Write the classification and applications of eutectics.
5. a)
Discuss briefly the mechanism of strain –hardening and state the factors that influence recrystallization. Explain the terms (i) stress relief,(ii) recrystallization, and (iii)grain growth.
b)
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4. a) b)
Describe the electroplating operation A nickel electroplating process consumes 20 amperes. What is the rate of deposition of nickel per hour if there are no side reactions?
7.
Solids are classified as metals, Semiconductors and insulators according their band structure. Explain in detail with diagrams.
8.
Explain the principle underlying the lamination of a transformer core, indicating how you would design it with reference to the direction of the eddy currents
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6. a) b)
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