Inorganic compounds permittivity

Liquid polyols are interesting among nonaqueous solvents because, like water and monoalcohols, they are hydrogen-bonded liquids with a high value of relative permittivity (Table 9.2.1), and therefore they are able to dissolve to some extent ionic inorganic compounds. Moreover, reactions can be carried out in such solvents under atmospheric pressure up to 250°C, i.e., at a temperature range higher than in water or monoalcohols such as methanol or ethanol. 

The data in Table 8.9 and Pigure 8.2 emphasize the very short liquid range of N2O4. Despite this and the low relative permittivity (which makes it a poor solvent for most inorganic compounds), the preparative uses of N2O4 justify its inclusion in this chapter. 

Liquid acetic acid is a hydrophilic (polar) protic solvent, similar to ethanol and water. With a moderate relative static permittivity (dielectric constant) of 6.2, it can dissolve not only polar compounds such as inorganic salts and sugars, but also non-polar compounds such as oils and elements such as sulfur and iodine. It readily mixes with other polar and non-polar solvents such as water, chloroform, and hexane. With higher alkanes (starting with octane) acetic acid is not completely miscible anymore, and its miscibility continues to decline with longer n-alkanes. This dissolving property and miscibility of acetic acid makes it a widely used industrial chemical. 

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