Class Test-02

Sub: Chemistry

Course: Chem-231F

Time: 1.30h

Marks: 5×14 = 70

1. What is inorganic benzene? Write down its important properties.
2. Draw the structure of Ice. Why does it float on water?
3. Write down the required conditions for the effective overlap between atomic orbitals.
4. BF₃ exists but BH₃ does not-explain why?
5. Ionization potential of oxygen atom is 13.61 eV but this value for oxygen molecule is 12.21 eV –explain why?
6. Terminal B-H distance is less than bridging B-H distance in borane molecule-explain.
7. Arrange the following compounds according to their increasing order of boiling points and explain the trend: CH₄, HF, NH₃ and H₂0
8. What is “styx” number? Draw all possible structures of B₆H₁₂ on the basis of this number.
9. Differentiate between formation enthalpy and lattice enthalpy.
10. Define hydration enthalpy. Write down the factors on which the hydration enthalpy of a substance depends?
11. What do you mean by diagonal relationship? Explain this on the basis of Fajan’s rule.
12. Draw the crystal structures of the following by using the hints given in table:

System	Radius of Cation (Å)	Radius of anion (Å)
MX	1.69	1.81
ZL2	1.12	1.31

13. Write down the factors affecting the strength and magnitude of van der Waals’ forces.
14. Explain the acidity of HX (X= F, Cl, Br and I) on the basis of hydrogen bond.