Manipal University 2010 B.Tech Chemical Science and Technology SECOND SEMESTER B.E END SEMESTER - - ENGINEERING CHEMISTRY (CHM 101/102) - Question Paper

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Note : Answer any five full questions. Draw neat and labelled diagram wherever necessary.

(i)    Describe the manufacture of water gas and mention its two important uses.

(ii)    Discuss the effect of organic additives on the nature of electrodeposits.

Distinguish the followings.

(a) Galvanization and tinning process (b) Concentration and kinetic polarization (c) Bulk and solution polymerisation (d) Galvanic and electrochemical series What is glass transition temperature? Explain any three factors that affect Tg.

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(i)    What are ion selective electrodes? Give the construction of glass electrode and describe the determination of pH of a solution by using it.

(ii)    What is a standard cell? Explain the potentiometric method of measurement of emf of a cell.

(i)    Explain the synthesis, properties and applications of styrene-butadiene rubber.

(ii)    What is reforming of petroleum? Give any two reforming methods.

(iii)    State and explain the type of corrosion occurring in the following example.

A steel pipe connected to copper plumbing.

(i) Polymer molecules with different degree of polymerization such as 500, 750, 850 and 1100 are mixed in molecular ratio 1: 2: 3: 4 in a sample of high polymer of styrene. Calculate the number average and weight average molecular weights.

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Derive the mathematical expressions for AG, AH and AS for a galvanic cell.

(i)    A sample of coal was analysed as follows. Exactly 2.5 g was weighed into a silica crucible. After heating for one hour at 110 ⁰C the residue weighed 2.415 g. The crucible was covered with a vented lid and strongly heated for seven minutes at 950 ⁰C. The residue weighed 1.528 g. The crucible was then heated without the cover until a constant weight was obtained. The last residue was found to weigh 0.245 g. Calculate the percentage of moisture content, volatile mater, ash and fixed carbon in the above sample.

(ii)    Briefly explain the effect of structure of polymer on chemical resistance and crystallinity.

Give reasons for the following:

(i)    High percentage of volatile matter is undesirable in a fuel.

(ii)    AG is positive in an electrolytic cell.

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