BCHCT-131 ATOMIC STRUCTURE, BONDING, GENERAL ORGANIC CHEMISTRY AND ALIPHATIC HYDROCARBONS
Solved Assignment 2019-2020
Atomic Structure, Bonding, General Organic Chemistry
and Aliphatic Hydrocarbons
Core Course in Chemistry
Course Code: BCHCT-131
Assignment Code: BCHCT-131/TMA/2019-2020
Maximum Marks: 100
BCHCT-131 Solved Assignment 2019-20
|Service Type||Solved Assignment (Soft copy/PDF)|
|Semester||2019-2020 Course: B.SC(G) CBCS|
|Short Name||BCHCT-131 (ENGLISH)|
|Product||Assignment of BSCG 2019-2020 (IGNOU)|
|Submission Date||This assignment is valid from 1st July, 2019 to 30th June, 2020. If you have failed in this
assignment or fail to submit it by June, 2020, then you need to get the assignment for the year
2020-21, and submit it as per the instructions given in the Programme Guide.
Note: Attempt all questions. The marks for each question are indicated against it.
1. What are the postulates of Bohr model of atom? Why was this model proposed by Bohr? (5)
2. What are matter waves? Explain in phase and out of phase waves using suitable diagrams. (5)
3. What are observables? Give the operators and operation for the following observables: (5)
(i) Position (x)
(ii) Momentum (P)
(iii) Potential Energy U(x)
(iv) Total Energy (E)
4. How are spherical polar coordinates related to the rectangular cartesian coordinates? Illustrate
giving suitable relations. Also write the Schrodinger equation for hydrogen atom in spherical polar
5. State and illustrate Hund’s rule and Pauli exclusion principle giving suitable examples. (5)
6. Derive the expression for the total energy of an electron in the n
th orbit. (5)
7. (a) The first ionisation energies of silicon and sulphur are lower than that of phosphorus.
(b) Explain the use of cation to anion radius ratio.
(c) Arrange the following according to the increasing order of covalence:
NaF, NaCl, NaBr, NaI
8. For the phosphite ion, (PO3)
(a) giving all the steps, write the Lewis structure.
(b) calculate the formal charges on O atoms and P atom.
(c) draw the shape of the ion.
9. Explain valence bond structures of carbon monoxide molecule. (5)
10. Draw the molecular orbitals formed by the s – s combination of atomic orbitals. Also illustrate the
electron densities for these orbitals and explain them.
11. What is structural isomerism? Explain its various types giving suitable examples. (5)
12. What are racemic mixtures? Discuss their resolution involving the formation of diastereomers. (5)
13. Draw Newman and sawhorse projections of various conformations of ethane. Compare the
stabilities of these conformations giving reasons.
14. Compare the relative acidities of ethanoic acid, propanoic acid, fluoroethanoic acid and
iodoethanoic acid. Explain your answer giving appropriate reasons.
15. Which is more stable in each pair given below? Give reasons for your answer. (5)
16. (a) Explain the following:
(i) Wurtz reaction, has limited synthetic applications.
(ii) Alkanes are relatively unreactive or do not react with most of the reagents.
(iii) Physical constants like boiling points, densities, etc. of alkanes generally increase with
increase in the number of carbon atoms.
(b) Give one example each of the following reactions:
(i) Sabatier-Senderens Reaction
(ii) Decarboxlylation of the carboxylic acid.
17. (a) Explain Satytzeff rule giving suitable example. (2)
(b) Give mechanism of the following reactions:
(i) Birch reduction
(ii) Wittig reaction
(iii) Dehydrohalogenation of alkyl halides
18. What is difference between Markownikoff’s and Markownikoff’s rules? Explain with suitable
19. (a) Explain the following terms: (2)
(i) Vicinal dihalide
(ii) Geminal dihalide
(iii) Stereoselective reaction
(iv) Poisoned catalyst.
(b) How would you prepare following compounds from an internal alkyne? Give the mechanism of
(ii) Ethanoic acid
20. (a) Give structure of the following:
(b) What is resonance energy? Explain in your own words. (3)
BCHCT-131, BCHCT 131, BCHCT131