Roll No. ......................

'>,:otalNo.ofQuestions: 09] Paper ID [CMIOl] [TotalNo.ofPages: 03r7 -(please till this Paper In in OMR Sheet)

B.Tech. (Semester - 1st & 2nd)

CHEMISTRY (CHM -101)

Time: 03 Hours Maximum Marks: 60

Instruction to Candidates:

1)

2)

3)

Section - A is compulsory. .

Attempt any Five questions from Section - B & C.

Select at least Two questions from Section - B & C.

Section - A . [Marks: 2 Each]

Ql)

a) What is the significance of break-point chlorination?

b) Why is methanol a good solvent for UV but not for IR determination?

c) Pyridine and ammonia are bases while they do not contain any hydroxylion. Explain.

d) Define the terms: Photosensitization and quenching.

e) Distinguish between EMF and electrode potential.

f) Why does magnesium , bicarbonate require double amount of lime forsoftening?

g) How many signals are observed in the NMR spectrum of chlorobenzene,acetaldehyde, ethanol and benzene?

h) Write the cell reaction for the cell:

Na(s)1 NaOH(aq) I IHz (g)J Pt

i) . Why qoes corrosion occur in steel pipe connected to copper plumbing?

j) What are degrees of freedom? How many degrees of freedom are presentin the system when a gas is in equilibrium with its solution in a liquid?

Section - B [Marks: 8 Each]~

Q2) (a) Describe the hot lime-soda process for the softening of water. Mentionits advantages over cold iime-soda process. -------..

(b) What is desalination? What are the methods available for desalination?Discuss anyone process in details.

Q3) (a) Describe the mechanjsm of electrochemical corrosion by (i) hydrogenevolution (ii) oxygen absorption. .

(b) What is Pillilfg-Bedworth ratio? How is it related to the protectivenessof an oxide layer?

(c) Give a brief account of cathodic protection method for preventingcorrOSIon.

Q4) (a) Account for the following:

(i) Ammonium chloride is used before precipitating group III cationsin inorganic analysis.

(ii) An aqueous solution of sodium acetate is.basic.

(b) At 298 K, calculate the pH of a 0.23 M weak monobasic acid havingionization constant 7.3 X 10-6.

Q5) (a) Calculate the emf of the cell:

,Zn(s)1 Zn2+ (0.2M) II.Ag + (0.002M) I Ag(s)

at 2SoC. Write down the cell reaction. The standard emf of the cell isl.S4V.

(b) Describe the construction of Ni-Cd battery with relevant reactionsoccurring during the discharge: Mention its application.

Section - C [Marks: 8 Each]

Q6) (a) State and explain Einstein law of photochemical equivalence. What ismeant by quantum yield of a photochemical reaction?

(b) For the photochemical formation of ethylene from d~-n-propyl ketone. using a radiation of wavelength 313 nm the quantum yield is 0.2l.

Calculate the number of moles of ethylene formed when the sample isirradiated with SOwatt of this radiation assuming that all the radiation isabsorbed by the sample.

,127) (a) Define the following:(i) Eutectic point

~.' (ii) Triple point

(b) State and derive Phase rule. What is reduced phase rule? Draw and explain

phase diagram of KI-H20 system.

Q8) (a) Three isomeric ethers are possible with the molecular formula C4HlOO.State how many signals will arise in the CarbOli-I3 NMR spectrum ofeach. Give explanation to your answer. .

(b) Explain the application of NMR spectroscopy to the following:

(i) Hydrogen bonding.

(ii) Structural diagnosis of keto-enol tautomers.

Q9) (a) Justify the following statements:

(i) Absorption bands are formed in ultra-violet spectrum instead ofsharp peaks.

(ii) Increasing the polarity of the solvent shifts 1[-71[* band tb longer

wavelength but n -7 1[* to shorter wavelengths.

(iii) Wavelength as well as extinction-coefficient increases with theincrease in conjugation in the compound.

(b) Define Frank-Condon principle and' give its importance in molecularspectroscopy.