VTU First Year Engineering (C Cycle) (Semester 1)
Engineering Chemistry
December 2013
Total marks: --
Total time: --
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

Choose the correct answers for the following:
1 (a) (i) A metal rod is dipped in a solution of its ions. Its electrode potential is independent of:
a) Temperature of solution
b) Concentration of solution
c) Area of metal exposed
d) Nature of metal
1 M
1 (a) (ii) The emf of a cell consisting of a SHE and a metal is formed to be 0.74V. The SHE is the positive electrode in the combination. Then the potential of the metal electrode is:
a) 0.74V
b) 1.74V
c) 0.37V
d) -0.74V
1 M
1 (a) (iii) Electrode potential of a metal in a dilute solution is:
a) Same as that in a concentrated solution
b) Lower than in concentrated solution
c) Higher than in concentrated solution
d) None of these
1 M
1 (a) (iv) The potential of the metal electrodes used in a cell are 0.35V and 0.85V. The emf of the cell formed by combining them is:
a) 1.20V
b) 0.5V
c) -0.50V
d) -1.20V
1 M
1 (b) What are concentration cells? Explain the working of a concentration cell by taking suitable example.
5 M
1 (c) Explain a method for determination of single electrode potential.
5 M
1 (d) An electrochemical cell consists of magnesium electrode in 0.042M Mg(NO3)2 solution and silver electrode in 0.35M AgNO3 solution. The SEP of Mg and Ag are -2.363V and +0.80V respectively. Represent the cell. Write the cell reaction and calculate the emf of the cell.
6 M

Choose the correct answers for the following:
2 (a) (i) In lead acid battery the product formed on both anode and cathode is
a) PbO2
b) PbO
c) PbSO4
d) Pb
1 M
2 (a) (ii) A battery in which a key component is seperated from the battery prior to its activation is called,
a) Primary battery
b) Secondary battery
c) Tertiary battery
d) Reserve battery
1 M
2 (a) (iii) In which of these batteries KOH is used as an electrolyte
a) Ni-Cd
b) Ni-MH
c) Zn-air
d) All of these
1 M
2 (a) (iv) In which of the following batteries the cell reaction is not reversible?
a) Pb-PbO2
b) Li-MnO2
c) Ni-MH
d) Ni-Cd
1 M
2 (b) Explain the construction and working of Zn-MnO2 battery.
5 M
2 (c) What are fuel cells? Describe the construction and working of a CH3OH-O2 fuel cell.
7 M
2 (d) Write the discharging and charging reactions in the following batteries:
i) Ni-Cd battery
ii) Ni-MH battery
4 M

Choose the correct answers for the following:
3 (a) (i) When a buried pipeline is protected from corrosion by connecting to magnesium block it is called:
a) Impressed voltage protection
b) Sacrificial cathode protection
c) Sacrificial Anodic protection
d) None of these
1 M
3 (a) (ii) During galvanic corrosion the more noble metal acts as:
a) Anode
b) Cathode
c) Anode as well as cathode
d) None of these
1 M
3 (a) (iii) In water line corrosion, the maximum amount of corrosion takes place
a) Along a line just above the level of water meniscus
b) Along a line at the level of water meniscus
c) Along a line just below the level of water meniscus
d) At the bottom of the vessel
1 M
3 (a) (iv) During differential aeration corrosion, the corrosion:
a) occurs at more oxygenated part
b) occurs at less oxygenated part
c) occurs uniform throughout
d) None of these
1 M
3 (b) What is mettalic corrision? Explain the electrochemical theory of corrosion with respect to iron.
6 M
3 (c) Explain the corrosion control techinque by cathodic protection.
6 M
3 (d) Explain galvanization process.
4 M

Choose the correct answers for the following:
4 (a) (i) In chromium plating electrolyte used in the bath solution:
a) H2CrO4+H2SO4
b) K2CrO4
c) HClO4+H2CrO4
d) None of these
1 M
4 (a) (ii) Printed circuit boards are prepared by the process of:
a) Electroplating
b) Electro polishing
c) Electroless plating
d) Electroforming
1 M
4 (a) (iii) The ability of the plating bath to develop uniform coating on the entire surface of the object is measured by its:
a) Current Density
b) Decomposition potential
c) Plating power
d) Throwing power
1 M
4 (a) (iv) Polarization effect can be minimized by using:
a) Large electrode surface
b) Highly conducting solution
c) Low electrolyte concentration
d) All of these
1 M
4 (b) Explain the terms:
i) Polarization
ii) Decomposition potential
6 M
4 (c) Explain the following plating variables affect the nature of electro deposit.
i) Current Density
ii) pH
iii) Complexing agent
6 M
4 (d) What is electroless plating? Explain electroless plating of copper.
4 M

Choose the correct answers for the following:
5 (a) (i) A knocking sound is produced in the internal combustion engine when the fuel:
a) Burns slowly
b) Burns fast
c) Contains rain water
d) None of these
1 M
5 (a) (ii) For good performance, the hydrocarbon molecules in a diesel fuel should be:
a) Straight chained
b) Branched chain
c) Side chained
d) Aromatic
1 M
5 (a) (iii) Catalytic cracking of heavy oil is carried out to get better quality
a) Kerosene
b) Diesel
c) Gasoline
d) Lubricating oil
1 M
5 (a) (iv) Suitability of diesel fuel is determined by:
a) Octane number
b) Propane number
c) Cetane number
d) Butane number
1 M
5 (b) Define calorific value. Explain how calorific value of solid fuel is determined by bomb calorimeter.
7 M
5 (c) 0.78g of coal containing 1.9% hydrogen, when burnt in a bomb calorimeter, increased the temperature of 2.7kg water from 27.2deg;C to 29.7deg;C. If the water equivalent of the calorimeter is 1.2kg, Calculate the gross and net calorific value. (Specific heat of water is 4.187kJ/kg/deg;C, latent heat of steam is 2457 kJ/kg)
5 M
5 (d) Explain the purification of silicon by zone refining process.
4 M

Choose the correct answers for the following:
6 (a) (i) For water system the maximum number of degrees of freedom
a) 0
b) 3
c) 2
d) 4
1 M
6 (a) (ii) When lead is progressively added to molten silver, the melting point of the resultant alloy is
a) raised
b) lowered
c) unaltered
d) unpredictable
1 M
6 (a) (iii) Colorimetric analysis is based on
a) Faradays Law
b) Beer-Lambert's Law
c) Ohm's Law
d) Kohlrauen's law
1 M
6 (a) (iv) In potentiometric titration the platinum electrode acts as:
a) Reference electrode
b) Standard electrode
c) Reduction electrode
d) Indicator electrode
1 M
6 (b) Draw phase diagram of Fe-C system. Explain eutectic and eutectoid point.
6 M
6 (c) Explain pattinson's process of desilverisation of lead.
4 M
6 (d) Discuss the theory and instrumentation of potentiometric titration.
6 M

Choose the correct answers for the following:
7 (a) (i) A plastic which can be softened in heating and hardened on cooling is called
a) thermoplastic
b) thermosetting
c) thermoelastic
d) thermite
1 M
7 (a) (ii) Which of the following is an elastomer
a) PVC
b) Bakelite
c) Nylon
d) Neoprene
1 M
7 (a) (iii) Chloroprene is the repeating unit in:
a) Polystyrene
b) Neoprene
c) PVC
d) Polythene
1 M
7 (a) (iv) The process of vulcanization makes rubber:
a) Soluble in water
b) Soft
c) Hard
d) More elastic
1 M
7 (b) What is glass transition temperature? Explain any three factors that influence the glass transition temperature.
4 M
7 (c) Explain the manufacture of plastic by compression moulding and injection moulding technique.
6 M
7 (d) Give the synthesis of
ii) Neoprene
6 M

Choose the correct answers for the following:
8 (a) (i) Total alkalinity of water is the sum of
a) OH- and CO32- only
b) OH- ions only
c) CO32- ions only
d) OH-, CO32- and HCO32-
1 M
8 (a) (ii) The indicator used in the determination of chloride content in water sample by argentometric method is
a) K3[Fe(CN)6]
b) K2CrO4
c) K2[Fe(CN)6]
d) K2CN2O7
1 M
8 (a) (iii) Primary treatment of sewage is used to remove:
a) Suspended and floating solids
b) Soluble inorganic solids
c) Pathogenic bacteria
d) All of these
1 M
8 (a) (iv) The reagent used in the estimation of sulphate by gravitimetric method is:
a) Phenol-di-sulphonic acid
b) Barium chloride
d) Barium sulphate
1 M
8 (b) Discuss the determination of chloride in water by argentometric method.
6 M
8 (c) How is alkalinity of water caused? Explain the determination of alkalinity by phenolphthalein indicator.
6 M
8 (d) Define COD. Explain the sewage treatment of activated sludge process.
4 M

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