CY2161 Engineering Chemistry II - Nov / Dec 2010 Question Paper

0
Anna University

B.E./B.Tech.Degree Examinations, November/December 2010

Regulations 2008

Second Semester

Common to all branches (except Marine Engg)

CY2161 Engineering Chemistry II


Time: Three Hours Maximum: 100 Marks

Answer ALL Questions

Part A - (10 x 2 = 20 Marks)

1. What i s single electrode potential?
2. De¯ne a reference electrode with an example.
3. What i s the e®ect of H2S gas when it comes into contact with iron metal?
4. What are organic inhibitors? What will be the reason for the increase in inhibiting
power of aliphatic amines in the following given order? NH3 < R3N.
5. With an example, state what is cracking.
6. Write the expression for the amount of air required for combustion of 1 kg fuel.
7. De¯ne the degrees of freedom in phase rule.
8. Mention any two advantages of alloy making.
9. What are chromophores? Give one example.
10. What is the principle of estimation of iron by colorimetry?

Part B - (5 x 16 = 80 Marks)

11. (a) (i) What is an ion selective electrode? Explain its principle and 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 i s 0.2415 V. (10)

OR

11. (b) Give a detailed account of conductometric titrations. (16)
12. (a) (i) Explain the sacri¯cial anode and impressed current techniques for the pre- vention of corrosion. (8)
(ii) What are the factors which in°uence chemical corrosion and electrochem- ical corrosion? (8)

OR

12. (b) (i) What are corrosion inhibitors? Classify different types of inhibitors with examples. (8)
(ii) What are the requisites of a good paint? Discuss the ingredients of a paint and explain their functions. (8)
13. (a) (i) How i s metallurgical coke manufactured by Otto Homann's 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 30±C- 400±C by fractional distillation of crude oil. (4)

OR

13. (b) (i) What i s 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)
14. (a) (i) Illustrate with an example how phase diagrams are drawn from thermal analysis data. (10)
(ii) Determine P and C and calculate F for the decomposition of CaCO3 in a closed vessel. CaCO3(s) CaO(s) + CO2(g) (6)

OR

14. (b) (i) Mention two non-ferrous alloys. Give their composition and uses. (6)

(ii) Name the different alloy steels and briefly explain their applications. (10)

15. (a) (i) Write the principle of UV spectroscopy. (6)
(ii) Write the mechanism of interaction between the vibrating molecule and infrared radiation. (6)
(iii) A solution of thickness 2 cm. transmitted 40% incident light. Calculate the concentration of this solution, given that the molar absorptivity is 6000 dm3. (4)

OR

15. (b) (i) With a neat diagram explain the principle, instrumentation and working of atomic absorption spectroscope. How will you estimate the amount of nickel using atomic absorption spectroscopy? (10)
(ii) Describe the steps involved in the determination of sodium ion concentration in a given sample solution using ame photometer. (6)
For the student , by the student , to the student !!