1. Describe the primitive cubic, body centered cubic and face centered cubic unit cells.
2. Compare quantum mechanical and bohr model of atom.
3. Draw molecular orbital energy diagrams for Li2 and Be2. What is the bond order in each of these species?
4. When calcium hydride (CaH2) reacts with water, hydrogen gas is evolved.
a) Write the chemical equation for the reaction.
b) If 5.00g of CaC2 reacts with, excess water, at 25 degrees C, what volume of H2 is collected at 760 torr? (Vapour pressure of water= 23.8 torr)
5)Estimate H'rxn for the reaction: CH4+Cl2--->CH3Cl+HCl where the average bond enthalpy in kj/mol. For C-H is 413 Cl-Cl is 242 C-Cl is 328 and H-Cl is 431.
6. The cyanate ion (NCO-)
a) Draw three lewis structures and state most valid.
b) Why isn't octet rule obeyed in one of the structures?
c) What is the hydridization of carbon in each structure?
The unit cell is the smallest repeat unit of a crystal structure.
Simple cubic: one atom in each corner of the cube
Body centred cubic: one in each corner and one in the centre of the cube
Face centred cubic: one in each corner and one in the centre of each face
The Bohr Model has an atom ...
The expert describes the primitive cubic, body centered cubic and face centered cubic unit cell.