Class Test-02
Sub: Chemistry
Course: Chem-231F
Time: 1.30h
Marks: 5×14 = 70
- What is inorganic benzene? Write down its important properties.
- Draw the structure of Ice. Why does it float on water?
- Write down the required conditions for the effective overlap between atomic orbitals.
- BF3 exists but BH3 does not-explain why?
- Ionization potential of oxygen atom is 13.61 eV but this value for oxygen molecule is 12.21 eV –explain why?
- Terminal B-H distance is less than bridging B-H distance in borane molecule-explain.
- Arrange the following compounds according to their increasing order of boiling points and explain the trend: CH4, HF, NH3 and H20
- What is “styx” number? Draw all possible structures of B6H12 on the basis of this number.
- Differentiate between formation enthalpy and lattice enthalpy.
- Define hydration enthalpy. Write down the factors on which the hydration enthalpy of a substance depends?
- What do you mean by diagonal relationship? Explain this on the basis of Fajan’s rule.
- 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 |
- Write down the factors affecting the strength and magnitude of van der Waals’ forces.
- Explain the acidity of HX (X= F, Cl, Br and I) on the basis of hydrogen bond.