B.Sc. 1st Semester Chemistry Question Paper BRABU Muzaffarpur

CBCS B.Sc. 1st Semester Chemistry Question Paper Session: 2023-2027 BRABU Muzaffarpur

Here you can find CBCS B.Sc. 1st Semester Chemistry Question Paper of Major, Minor and multidisciplinary Session: 2023-2027 BRABU Muzaffarpur

MJC 1st Semester 2023

Exam Date: 20.12.2023
Time: 3 Hours
Full Marks: 70

Candidates are required to give their answer in their own words as far as practicable.
The figure in the margin indicate full marks.
Answer from all the groups are directed.

Group-A
Compulsory

1. Chose the correct answer of the following 2 × 10 = 20

a. Identify the isotopic pair among the following-
i. ₁₁X²³ and ₁₁X²⁴
ii. ₆X¹⁴ and ₇X¹⁴
iii. ₂₀X⁴⁰ and ₁₉X³⁹
iv. None of these

b. Lyman series of spectral line of hydrogen atom lines in
i. UV region
ii. Visible region
iii. IR region
iv. None of these

c. Naphthalene is
i. Aliphatic compound
ii. Cyclo alkane
iii. Alkane
iv. None of these

d. Which among the following carbocation is most stable?
i. C₆H₅CH₂⁺
ii. (C₆H₅)₂CH⁺
iii. C₆H₅⁺
iv. (C₆H₅)₃C⁺

e. Which among the following species are paramagnetic-
i. B₂
ii. O₂
iii. N₂⁺
iv. All of these

f. A hydrcarbon has the molecular formula C₅H₁₀. It would be-
i. Alkane
ii. Cycloalkane
iii. Alkyne
iv. None of these

g. The bond order of He₂⁺ is-
i. 1.0
ii. Zero
iii. 0.5
iv. 1.5

h. Which among the following contains a chiral carbon atom-
i. CH₄
ii. CH₃Cl
iii. CH₂Cl₂
iv. CH(CH₃)ClBr

I. Aqueous solution of sodium succinate on electrolysis gives-
i. Ethane
ii. Ethyne
iii. Ethene
iv. CO₂

j. Which among the following compound will exhibit geometrical isomerism-
i. 2-butene
ii. 2-butyne
iii. 2-butanol
iv. all of these

Group-B
Answer any FOUR questions of the following
5 × 4 = 20

2. Write electronic cofiguration of
Na(11), V(23), Ag(47), Ni⁺²(28), Ce(24)
3. Explain electrophiles and nucleophiles. Give examples.
4. Which one has larger bond angle and why?
NH₃ and H₂O
5. 1-butyne gives white ppt with ammonical silver nitrate but 2-butyne does not. Explain.
6. Discuss the necessary condition for a compound to be optical active.
7. Explain de-Broglie hypothesis for dual nature of matter.

Group-C
Answer any THREE questions of the following
10 × 3 = 30

8. a. Describe the four quantum numbers and their significance to describe an electron in an atom.
b. What is Pauli's eclusion principle.
9. Give the hybridization of central atom, structure and shape of the following-
CO₃^-2, XeOF₄, ICl₂^-, SF₄^-, NCl₃
10. a. Explain Markovnikov's rule and anti Markovnikov's rule with suitable example.
b. Discuss the ozonolysis reaction on 2-ethylpent-2-ene.
11. Explain any four of the following-
a. Hyperconjugation
b. Enantiomer
c. Eclipsed and staggered ethane
d. R-S configuration
e. Born-Haber cycle
f. Normalised wave function
12. a. Why the carbon-carbon bond length in benzene is shorter than carbon-carbon single bond but longer than carbon-carbon double bond.
b. Arrange the followin in increasing order of acidic sterngth. Give reason for your answer.
CH₂FCOOH, CHF₂COOH, CH₃COOH,CH₂ClCOOH.