Unformatted text preview: 111. Chapter 3:
A. Organic chemistry:
It involves dealing with compounds with C, H, N, and O in them. B. Empirical formula: 1. It is something we can obtain by burning a molecule. 2. If we burn an organic compound we get 002, H20, and N20 and so on. 3. If we collect these gases and weigh them after removing the oxygen used
in burning we get a representation which will give the no. of moles of different
elements in a compound.
a. For example: CxHyNzOz etc.
b. Consider vinegar and glucose: Both give same empirical formula (CHZO)
c. So empirical formula doesn’t provide much information about the compound. C. Molecular Formula:
1. Consider C2H402: this is not an empirical formula
Molecular weight of this compound is 60.0 where as for CH20 it is 30.0. So to form
C2H402 we require 2 molecules of CHZO.
D. It gives the arrangement of the atoms in a molecule
1. Consider C2H402: Acetic Acid HO I ll
H — C — C — O — H
H 2. Structural formula is the most important formula. .
3- For molecular compounds, bonds are unidirectional. So the arrangements of atoms Matter and many such arrangements are possible. Hence, only structural formula is unambiguous and identifies the compound. E. Covalent Bonds:
1. Electrons are shared between pairs. Two elements in an compound are connected or
related by what is called a covalent bond.
2. Covalent Bonds can be single or double or triple.
3. In covalent bonds every pair is related in a different way. ...
View Full Document
- Fall '07