BCHCT133 EM 2023 JAN TO DEC SOLVED ASSIGNMENT

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ASSIGNMENT
CHEMICAL ENERGETICS, EQUILIBRIA AND FUNCTIONAL ORGANIC
CHEMISTRY I
Core Course in Chemistry
Course Code: BCHCT-133
Assignment Code: BCHCT-133/TMA/2023
Maximum Marks: 100
Note: Attempt all questions. The marks for each question are indicated against it.
PART A: CHEMICAL ENERGETICS AND EQUILIBRIA (50)
1. (a) State Zeroth law of thermodynamics and give the requirement for thermal equilibrium. (2)
(b) Differentiate between a closed and an isolated thermodynamic system with the help
of suitable examples. (3)
(c) 0.25 mol of an ideal monoatomic gas undergoes isothermal expansion from a volume
of 2.0 dm3
to 10 dm3
at 27C. Calculate the maximum work that can be obtained
from this process. (5)
2. (a) Calculate the amount of heat required to increase the temperature of 2.00 moles of
Argon gas from a temperature of 200 K to 500 K under isobaric conditions.
[Given: Cp,m = 20. 79 J K1mol1
] (2)
(b) Calculate ΔHº for the reaction
CO2(g) + H2(g)  CO(g) + H2O(g)
Given: H for CO2(g), CO(g) and H2O(g) are 393.5, 111.31 and 241.80 kJ mol–1
respectively. (3)
(c) Differentiate between enthalpy driven and entropy driven reactions with the help of
suitable examples. (5)
3. (a) Define enthalpy of atomisation. The enthalpy of atomisation of graphite is found to be
715 kJ mo11
, write the thermochemical equation for the process. (2)
(b) Derive an expression for isothermal mixing of ideal gases. (3)
(c) Fossil fuels are being replaced with hydrogen, much of it is being derived from
methane, CH4, in natural gas which uses the forward reaction of the equilibrium: (5)
CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g)
What will be the expression for Kc for the above reaction? (5)
4. (a) The successive ionisation constants of polyprotic acids are smaller and smaller.
Explain. (3)
4
(b) Determine the acid-base nature of the aqueous solution obtained by dissolving
NaNO2
in water to get 0.01 M solution at 298 K. [Given% Ka (HNO2) = 4.5  10−4] (3)
(c) Consider the equilibrium PCl3(g) + Cl2(g) ⇌ PCl5(g), This reaction is endothermic.
What will be the change in the concentration of Cl2 a) more PCl3 is added b) more
PCl5 is added c) temperature is increased and d) the volume of the container is
reduced. (4)
5. (a) The sulphides of group IV cations are not precipitated in Group II. Explain. (2)
(b) Arrange propanoic acid, ethanoic acid and 2-chloroethanoic acid in the increasing
order of their acidities giving reasons. (3)
(c) The solubility product of AgCl is 1.8  10−10. Calculate the concentration of chloride
ions required to precipitate silver ions from its 0.01 M solution. (5)
PART B: FUNCTIONAL GROUP ORGANIC CHEMISTRY-I (50)
6. (a) Complete the following reactions: (5)
(i) OH
+ Zn 
(ii)
CH3
(CH2
)5CH3
Pt
670 K
(iii)
AlCl3
+ CH3COCCH3
O O
(iv) CH2CH3 Cl2
hv
(v) NO2
HNO3
/H2SO4
(b) Write the product for the following reaction. Explain product (s) formation using its
mechanism.
H3C C CH2
CH3
CH3
Br
H2O
(5)
7. (a) Why alkenyl and aryl halides are less reactive towards nucleophilic substitution? (5)
(b) What is the best way to convert alcohol to alkyl halides? Explain with suitable
examples.
(5)
5
8. (a) How you will carry out following conversions? Write all the steps involved in these
conversions.
(5)
(i) OH OH
Br
(ii) OH OH
CHO
(b) Identify suitable alkyl halides for the preparation of anisole and MTBE. Justify your
answer.
(5)
9. (a) Distinguish between crown ethers and cryptands. (5)
(b) Find out suitable reagents for the following conversions: (5)
(i)
H3C
H
OH
H3C
H
O
(ii)
RC CR RCH2 CR
O
(iii) RCOCl RCHO
(iv)
H3C C CH3
O
(CH3
)
2C C(CH3
)
2
(v) O
N(R)2
10. Write the mechanism of the following reactions: 10
(a) Acid-catalyzed enolisation
(b) Claisen-Schmidt reaction