Apolar - Apolar
The apolar molecules are those molecules that are produced by the union between atoms that have the same electronegativity , so the forces with which the atoms that make up the molecule attract the electrons of the bond that are equal. A molecule is polar when one end is positively charged and the other is negatively charged. When a molecule is apolar, these charges do not exist. [ 1 ]
The term hydrophobic is often used for an apolar substance, due to the similarity of behaviors: a hydrophobic is one or that which repels or hates water [ 2 ] and non-polar substances do not dissolve in water despite being liquid (such as the oil ). Water is a polar solvent , [ 3 ] and therefore can only house polar molecules . This is based on the fact that at microscopic levels, something dissolves in a substance when molecular bridges appear between the solvent and solute particles . These bridges (orintermolecular forces ) appear between the areas with different charges in both substances. Water is a polar molecule (it has two areas with different charges, positive and negative) and whatever you want to dissolve in it, it must be polar, in order to establish such bonds.
- Covalent molecules made up of equal atoms. Examples: hydrogen (H 2 ); oxygen (O 2 ); nitrogen (N 2 ); sulfur (S 8 ).
- Covalent molecules formed by atoms of similar electronegativity. For example, molecules made up of carbon (C) and hydrogen (H): methane (CH 4 ); butane (C 4 H 10 ); cyclohexane (C 6 H 12 ).
- Molecules formed by atoms of different but with a symmetric structure such that polarity is canceled: carbon dioxide (CO 2 ); carbon tetrachloride (CCl 4 ); carbon disulfide (CS 2 ) or dimethyl ether (H 3 C-O-CH 3 ).
Offset printing technology
In the hydrophobic areas of the plate image, water is repelled, being the ink that adheres to these areas, since the offset printing system is based on a water-ink balance.
- Chemistry. Specific Test. University Access Test for Seniors ... , p. 99, in Google books
- Montés, Fernando Jordán (2013). The universe of insects . Mundi-Press Books. ISBN 9788484766384 . Retrieved January 29, 2018 .
- Weininger, Stephen J .; Stermitz, Frank R. (1988). Organic chemistry . Reverte. ISBN 9788429175271 . Retrieved January 29, 2018 .