Solvents play an important role in altering the strength of an acid or a base. For example, take the case of salvation of amines in water. As we know methyl group has electron inductive effect and expected order of basic strength is

                                                      R₃N > R₂NH> RNH₂
However, tertiary amines are weaker bases than primary amines. This trend could be explains on the basic of satiric effect but in gaseous state the basicity of methyl amines show regular gradation
                                                     H₃N < MeNH₃ < Me₂NH < Me₃N
Showing the absence of satiric effect. This means that the anomaly of lowered basicity of Me₃N lies only in the effect of solvent. When amines are dissolved in water, ammonium ion is formed which undergo hydration thorough hydrogen bonding. The greater the number of hydrogen bonds formed by the ammonium ion of the base amine, the larger would be the hear of hydration.

The energy of hydration of ammonium ions decreases in the order RNH₃⁺  > R₂NH₂⁺ >R₃NH⁺ as shown in . This order of basicity due to salvation is totally opposite of the basicity due to inductive effects. Thus, basicity of an amine in solution is the combine effect of inductive effect of constituents and the extent of solution of the conjugate acid of the base. As a consequence of the combined effect, dialkttamines are the strongest bases among amines and tertiary amines are weaker than secondary amine and sometime weaker than primary amines even.

Solvents play an important role in altering the strength of an acid or a base. Non-aqueous solvents like ammonia, amides ( RCONH₂ ) , hydrazine, etc. are good proton acceptors and hence will help acids to ionic in them. Consequently, in a basic solvent, all acids tend to become strong. Such solvents are said to exert a leveling effect on the strength of acids. The reverse is true of acidic solvents like CH₃COOH, HCOOH, hydrogen halides, etc., in which all bases tend to became strong but most acids became relatively weak or may even ionize as a base. Such acidic solvents tend to exert differentiating effect on the strength of acids.

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