B.Sc. Chemistry-Honours 1st Paper

B.Sc. Chemistry-Honours 2nd Paper

First Paper Chemistry Honours BRABU Muzaffarpur

Year 2022

1. a. Why do real gas deviates from ideal behavior ?
b. Evaluate the critical constant in terms of Vander Waal's constant.
c. Describe law of corresponding state.
2. a. Define specific and molar conductances. How do they vary with dilution.
b. Define ionic mobility and transport number and explain them.

3. a. What is phase rule ? Draw phase diagram of ice-water-vapor system.
b. Explain Triple point.
4. Write explanatory notes on any two of the following-
a. Trouton's rule
b. Parachore and chemical constitution
c. Vapor pressure and its determination
d. Kopp's law

5. a. Define ionization energy, electronaffinity and electronegativity. How do they vary in periodic table.
b. Discuss the structure of diborane.
6. a. Predict the shape and hybridization of the following-
BeCl2, SO2, H2O and I2
b. Define dipole moment. Expalin the polarity in the following molecules-
NH3, BF3 and CH4

7. a. Give a comparative study of s-block elements.
b. Discuss the diagonal relationship between boron and silicon.
8. a. Draw the molecular orbital diagram of O2+, O2 and O2. Explain their magnetic properties and relative bond orders.
b. What is Born-Haber cycle ? Explain.

9. Expalin any three of the followings-
a. Borazine
b. Alkyl organometallic
c. Lattice energy
d. Solvation energy


1. a. Derive Vander Waals equation.
b. What are units of Vander Waals constants 'a' and 'b'?
c. Explain Boyle temperature.
2. a. Explain Phase component and degree of freedom.
b. Explain phase diagram of KI-H2O system.

3. a. What is Kohlrausch law? What are its applications?
b. Write notes on cell constant.
4. Write notes on any two of the following:
a. Effect of dilution on conductance
b. Migration of ions
c. Vapour pressure
d. Viscosity

5. a. Why cation is smaller in size than its parent atom?
b. Define atomic radius and explain its variation in period and group of the periodic table.
c. Why anion is larger in size than parent atom?
6. a. Explain VSEPR theory.
b. Predict hybridisation, structure and shape of the following:
i. PCI5
ii. I3
iii. SF6
iv. XeF6
v. NO3

7.a. Explain bonding anti-bonding and non-bonding molecular orbitals.
b. Explain bond order with example.
c. How will you prove that O2 is paramagnetic?
8. Write short notes on the following:
a. Diagonal relationship in Periodic Table
b. M.O. diagram of B2
c. Hydrogen Bond
d. Fajan's rule
9. Name all the alkaline earth metals and write down their atomic number and electronic configuration.
b. What is difference between σ and π bond
c. Define and explain electronegativity.


Due to COVID, exam was held in MCQ mode in 2020. MCQs with Answer



5. a. Define ionization potential and explain why ?
i. Ionization potential of Li is greater than Na
ii. Ionization potential of Na is less than Mg
iii. First ionization potential of K is less than Ca but second ionization potential is high.
6. a. Name alkali metals and give their electronic configuration.
b. Discuss the variation of thermal stability of BeCO3, MgCO3, CaCO3 and SrCO3
c. The solubilities of sulphates of alkaline earth metals decreases on moving down the group. Justify.

7. a. What do you mean by dipole moment.
b. Which among the following pairs has high dipole moment
i. CO2 and NO2
ii. HF and HCl
iii. o-dichlorobenzene and p-dichlorobenzene
c. What is unit of dipole moment
8. a. Sulphur forms SF4 and SF6 but oxygen does not form OF4 and OF6, why ?
b. Discuss the variation in b.p. of H2O, H2S, H2Se and H2Te
c. Which among H2SO3 and H2SO4 are more acidic ?
d. Write down the structure of peroxodisulphuric acid
9. a. Give the shape, structure and hybridization of the following-
XeF2, CO3-2, BrF3, SF4 and AF5
b. Write the resonating structure of NO3-


1. a. Describe the deviation of real gas from ideal behavior.
b. State vander waal equation and explain the significance of vander waal constant.
c. What is Boyle’s temperature.
2. a. What do you mean by vapour pressure of a liquid. Give a method for its determination.
b. Explain the term parachore. Discuss its utility in the elucidation of structure of molecules.

3. a. Define
i. Number of phases
ii. Degree of freedom
iii.Number of component with suitable example
b. State and explain phase rule. Give example.
4. a. Explain any two of the following: i. Kohlrausch’s law
ii. Cell constant
iii. Specific constant
b. The molar conductivities of NaCl, HCl and sodium acetate are 126.4, 425.9 and 91.0 scm2mol-1 respectively at infinite dilution. Calculate the molar conductance of CH3COOH at infinite dilution.

5. a. Name all the alkaline earth metals and write down their atomic number and electronic configuration.
b. How will you account for any three of the following:
i. KOH is stronger base than Ba(OH)2
ii. Lattice energy varies as LiF > NaF > KF > RbF > CsF
iii. The conductivity of Li+ in aqueous solution is less than that of Cs+
iv. Na gives golden yellow color in flame
6. a. Draw molecular orbital energy level diagram for oxygen molecule.
b. Arrange the following in order of increasing bond length-
O2+, O2 and O2-
Identify the species which are paramagnetic among the above.
c. What is difference between σ and π bond.

7. a. Identify the group and period of the following elements in the periodic table-
Mg(12), Sn(50), Ag(79) and Ce(58)
To which block of the periodic table they belong.
b. Which among Ti(22), V(23), Cr(24) and Mn(25) has the maximum second ionization energy.
c. Define electronegativity.
8. a. Give the structure difference of diamond and graphite.
b. Describe the structure of fullerenes.
c. Why CO2 is gas but SiO2 is solid ?

9. a. Explain any two of the following-
i. Oxyacids of phosphorus
ii. Inert pair effect
iii. Inter halogen compounds
b. Give the hybridization, structure and shape of PCl3 and PCl5