The properties of materials

1. How to prepare a schlenk tube


http://www.youtube.com/watch?v=_seF9s6fq9A



Properties of materials

Why do ionic compound dissolve in water :
When an ionic compound is introduced into a polar solvent (water) ions cause the glass surface around the molecules orientation dipolar ion facing towards each end with opposite charge to that of the same

Why do covalent compound dissolve in acetone? 
Acetone dissolves both polar and non-polar substances because it has both polar and non-polar parts. The formula is (CH3)2C=O. It has two methyl groups, which are non-polar (they look like hydrocarbons), but it also has a polar carbonyl (C=O) group, which can solvate more polar compounds.

				Why do metal conduct electricity? Metals are good conductors because they have unfilled space in the valence energy band. Also,metals are soft, has a low melting point and happens to be reactive thats why they can easily conduct heat/electricity easily. Why do covalent compounds NOT conduct electricity? Conditions for conducting electrciity are free electrons that can move throughout the structure and carry charge. In covalent compounds, there are no free electrons so covalent compounds do not conduct electricity.. Why do ionic compounds have such high boiling points? Ionic compounds form very strong bonds, and the energy required to break these bonds is much higher than seen in most other bonds. The energy required for an ionic solid to melt (temperature at melting point) is therefore high, and even higher for the boiling point of course.  Why do metals have such high boiling points? There is NO IONIC BONDING in metals. It is metallic bonding which is something totally different.  Metallic bonding involves a "sea of electrons" delocalised in a vast array of molecular orbitals that extend over the metal atoms.