One critical factor in determining the strength of acids can be the strength of the HA bond. Clearly if the proton is very tightly held by the rest of the molecule, it will require a lot of energy to remove it, and hence the acid will be weak. Equally, a weakly-held proton is a characteristic of a strong … Read more
Organic acids have a wide range of strengths. The following discussion will explain some of the trends observed, by reference to Brønsted acids. For example, consider the difference between ethanol and ethanoic acid. The two molecules both have an acidic proton (H+) attached to a heteroatom (in this case, oxygen): Deprotonation of ethanol: Deprotonation of ethanoic acid: So why does ethanoic acid … Read more
The strength of an acid can be determined by considering the extent to which it dissociates in a given solvent (i.e. to which side this equilibrium lies): The equilibrium constant in water is given by: Note that the H2O term has been incorporated into Ka, as water (the solvent) is in vast excess, and hence the value of its concentration will … Read more
There are several definitions of acids and bases. The two most useful and most commonly encountered are the Lewis and Brønsted definitions. According to Brønsted, an acid is a species that has a tendency to lose a proton, and a base is a species with a tendency to gain a proton. According to Lewis, an acid is a species … Read more
Decalins are the most important members of group of molecules called fused rings. The name, as it might suggest, applies to molecules which have two adjacent rings, which have two atoms in common. Decalins are two fused cyclohexane rings, and can occur in two isomers: cis and trans: The forms get their names from the relative position of the two … Read more