Anna University Chennai 2012-2nd Sem B.E /B.tech /e , ester, , subject code:CY2161, ENGINEERING CHEMISTRY ll (regulation 2008) - Question Paper

Question Paper Code : 10283

B.E./B.Tech. DEGREE EXAMINATION, MAY/JUNE 2012.

Second Semester Common to all branches (Except Marine Engineering)

CY 2161/183202/CY 24/080010002 ENGINEERING CHEMISTRY II

(Regulation 2008)

Time : Three hours    Maximum : 100 marks

Answer ALL questions.

PART A (10 x 2 = 20 marks)

1.    Construct a cell with Fe and Mg at standard conditions and calculate the Emf developed. Given : E(Fe²⁺/Fe) =-0.44 V and E(Mg²⁺/Mg)=-2.37 V.

2.    Zinc reacts with dilute H2SO4 to give hydrogen but Ag does not - Explain.

3.    Mention the types of corrosion.

4.    What are organic inhibitors? What will be the reason for the increase in inhibiting power of aliphatic amines in the following given order? NHa < RNHs < R₂NH<R₃N.

5.    The ultimate analysis of a coal sample indicates Carbon = 84%, Sulphur =

1.5%, Nitrogen = 0.6%, Hydrogen = 5.5% and Oxygen = 8.4%. Calculate the GCV.

6.    Write the expression for the amount of air required for combustion of 1 kg fuel*

7.    NH4C1(s) <=> NH3 (g) + HC1 (g). How many phases, components and degrees of freedom are available in this equilibrium?

8.    Write the chemical compositions of Dutch metal and Gun metal.

9.    Mention any two applications of UV spectroscopy.

10.    State the principle involved in colorimetric analysis.

11.    (a) (i) What is an ion selective electrode? Explain its principle and

Question Paper Code : 10283

working.    '    (6)

(ii) Derive an expression for Nernst equation; The emf of a cell measured by means of a hydrogen electrode against a saturated calomel electrode at 298 K is 0.4188 V. If the pressure of the H2 (g) was maintained at 1 atm, calculate the pH of the unknown solution, given the potential of reference calomel electrode is 0.2415 V. (10)

Or

(b) (i) Draw the conductometric titration curve of strong acid versus strong base and explain it.    (4)

(ii)    Explain with suitable examples any two applications of emf series.

(4)

(iii)    Explain the potentiometric titration of FeS04, vs. K2Cr207 with a neat diagram.    (8)

12.    (a) (i) State the differences between chemical corrosion and

electrochemical corrosion.    (6)

(ii) Write a detailed note on cathodic protection methods.    (10)

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(b) (i) Discuss the various steps involved in electroless nickel plating. (8)

(ii) Explain the different types of inhibitors used to control the corrosion rate.    (8)

13. (a) (i) How is metallurgical coke manufactured by Otto Hoffmanns method? What are the important by products recovered from coke oven gas?    (8)

(ii)    Describe the significance of ultimate analysis of coal.    (4)

(iii)    List the'fractions of hydrocarbons collected between boiling range of 30C 400 C by fractional distillation of crude oil.    (4)

Or

(b) (i) What is hydrogenation of coal? Write the Fischer-Tropsh process of manufacture of liquid fuels from solid fuels.    (8)

(ii) Write in detail chemical reactions involved in the manufacture of producer gas and mention its chemical composition.    (8)

State phase rule and explain the terms involved.    (8)

Draw and explain the phase diagram of two component system with an example.    (8)

Or

Write short notes on any four methods of heat treatment of steel. (8) Give the composition and uses of the following alloys

(1)    Nichrome

(2)    Stainless steel

(3)    Brass

(4)    Bronze.    (8)

Write the principle of UV spectroscopy.    (6)

Write the mechanism of interaction between the vibrating molecule and infra-red radiation.    (6)

A solution of thickness 2 cm. transmitted 40% incident light. Calculate the concentration of this solution, given that the molar absorptivity is 6000 dm³ mol^-1 cm^-1.    _______....... X4)

Or

Explain briefly the principle of a flame photometer. A sample solution is found to contain KC1 and NaCl. How will you determine the amount of NaCl alone present in the solution using a flame photometer?    (10)

Compare : Flame photometry and Atomic absorption spectroscopy.

(6)

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Attachment: anna-university-chennai-2012-b-e-11558-1.pdf

Earning:   Approval pending.