Engineering Chemistry 2 - May 2012

First Year Engineering (Semester 2)

TOTAL MARKS:
TOTAL TIME: HOURS

1 Construct a cell with Fe and Mg at standard conditions and calculate the Emf developed. Given: E^o (Fe²⁺/Fe)=0.44 V and E^o (Mg²⁺/Mg)=-2.37 V.(2 marks) 10 State the principle involved in colorimetric analysis.(2 marks)

Answer any one question from Q11 (a) & Q11 (b)

11 (a) (i) What is an ion selective electrode? Explain its principle and working.(6 marks) 11 (a) (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 marks) 11 (b)(i) Draw the conductometric titration curve of stronge acid versus strong base and explain it.(4 marks) 11 (b)(ii) Explain with suitable examples any two applications of emf series.(4 marks) 11 (b)(iii) Explain the potentiometric titration of FeSO₄ vs K₂Cr₂O7 with a neat diagram.(8 marks)

Answer any one question from Q12 (a) & Q12 (b)

12 (a) (i) State the differences between chemical corrosion and electrochemical corrosion.(6 marks) 12 (a) (ii) Write a detailed note on cathodic protection methods.(10 marks) 12 (b) (i) Discuss the various steps involved in electroless nickel plating.(8 marks) 12 (b) (ii) Explain the different types of inhibitors used to control the corrosion rate.(8 marks)

Answer any one question from Q13 (a) & Q13 (b)

13 (a)(i) How is metallurgical coke manufactured by Otto Hoffmann's method? What are the important by products recovered from coke oven gas?(8 marks) 13 (a)(ii) Describe the significance of ultimate analysis of coal.(4 marks) 13 (a)(iii) List the fractions of hydrocarbons collected between boiling range of 30°C-400°C by fractional distillation of crude oil.(4 marks) 13 (b) (i) What is hydrogenation of coal? Write the Fischer-Tropsh process of manufacture of liquid fuels from solid fuels.(8 marks) 13 (b) (ii) Write in detail chemical reactions involved in the manufacture of producer gas and mention its chemical composition.(8 marks)

Answer any one question from Q14 (a) & Q14 (b)

14 (a) (i) State phase rule and explain the terms involved.(8 marks) 14 (a) (ii) Draw and explain the phase diagram of two component system with an example.(8 marks) 14 (b) (i) Write short notes on any four methods of heat treatment of steel.(8 marks) 14 (b) (ii) Give the composition and uses of the following alloys
(1) Nichrome
(2) Stainless steel
(3) Brass
(4) Bronze.(8 marks)

Answer any one question from Q15 (a) & Q15 (b)

15 (a) (i) Write the principle of UV spectroscopy.(6 marks) 15 (a) (ii) Write the mechanism of interaction between the vibrating molecule and infra-red radiation.(6 marks) 15 (a) (iii A solution of thickness 2 cm. Transmitted 40% incident light. Calculate the concentration of this solution, give that the molar absorptivity is 6000 dm² mol^-1 cm^-1(6 marks) 15 (b) (i) Explain briefly the principle of a flame photometer. A sample solution is found contain KCL and NaCI. How will you determine the amount of NaCI alone present in the solution using a flame photometer?(10 marks) 15 (b) (ii) Compare: Flame photometry and Atomic absorption spectroscopy.(6 marks) 2 Zinc reacts with dilute H₂SO₄ to give hydrogen but Ag does not- Explain.(2 marks) 3 Mention the types of corrosion.(2 marks) 4 What are organic inhibitors? What will be reason for the increase in inhibiting power of aliphatic amines in the following given order? NH₃ < RNH₃ < R₂NH < R_3N.(2 marks) 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.(2 marks) 6 Write the expression for the amount of air required for combustion of 1 kg fuel.(2 marks) 7 NH₄Cl(s)⇔ NH₃(g)+HCl(g). How many phases, components and degrees of freedom are available in this equilibrium?