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  2. Benzoic acid - Wikipedia

    en.wikipedia.org/wiki/Benzoic_acid

    Benzoic acid is cheap and readily available, so the laboratory synthesis of benzoic acid is mainly practiced for its pedagogical value. It is a common undergraduate preparation. Benzoic acid can be purified by recrystallization from water because of its high solubility in hot water and poor solubility in cold water. The avoidance of organic ...

  3. Hammett equation - Wikipedia

    en.wikipedia.org/wiki/Hammett_equation

    The starting point for the collection of the substituent constants is a chemical equilibrium for which the substituent constant is arbitrarily set to 0 and the reaction constant is set to 1: the deprotonation of benzoic acid or benzene carboxylic acid (R and R' both H) in water at 25 °C. Scheme 1. Dissociation of benzoic acids

  4. List of physical constants - Wikipedia

    en.wikipedia.org/wiki/List_of_physical_constants

    The constants listed here are known values of physical constants expressed in SI units; that is, physical quantities that are generally believed to be universal in nature and thus are independent of the unit system in which they are measured. Many of these are redundant, in the sense that they obey a known relationship with other physical ...

  5. Van der Waals constants (data page) - Wikipedia

    en.wikipedia.org/wiki/Van_der_Waals_constants...

    The following table lists the Van der Waals constants (from the Van der Waals equation) for a number of common gases and volatile liquids. [ 1 ] To convert from L 2 b a r / m o l 2 {\displaystyle \mathrm {L^{2}bar/mol^{2}} } to L 2 k P a / m o l 2 {\displaystyle \mathrm {L^{2}kPa/mol^{2}} } , multiply by 100.

  6. Taft equation - Wikipedia

    en.wikipedia.org/wiki/Taft_equation

    where log(k s /k CH 3) B is the ratio of the rate of the base catalyzed reaction compared to the reference reaction, log(k s /k CH 3) A is ratio of a rate of the acid catalyzed reaction compared to the reference reaction, and ρ* is a reaction constant that describes the sensitivity of the reaction series. For the definition reaction series, ρ ...

  7. List of boiling and freezing information of solvents - Wikipedia

    en.wikipedia.org/wiki/List_of_boiling_and...

    Hydrochloric Acid: 84.8 [13] tert-Butanol: 82.5 [14] Chlorobenzene: 131.7 [15] p-chlorobenzotrifluoride: 1.34 136 –36.1 [16] MTBE: 55.2 [17] Pentane: 36.1 [18] Petroleum Ether: 35.0-60.0 [19] Cyclopentane: 49.3 [20] Isopropanol: 82.3 [21] Dichloromethane: 1.33 39.8 [22] n-Propanol: 97.2 [23] Pyridine: 115.3 [24] Dimethylacetamide: 166.1 [25 ...

  8. 4-Hydroxybenzoic acid - Wikipedia

    en.wikipedia.org/wiki/4-Hydroxybenzoic_acid

    4-Hydroxybenzoic acid, also known as p-hydroxybenzoic acid (PHBA), is a monohydroxybenzoic acid, a phenolic derivative of benzoic acid.It is a white crystalline solid that is slightly soluble in water and chloroform but more soluble in polar organic solvents such as alcohols and acetone. 4-Hydroxybenzoic acid is primarily known as the basis for the preparation of its esters, known as parabens ...

  9. Van 't Hoff factor - Wikipedia

    en.wikipedia.org/wiki/Van_'t_Hoff_factor

    Dimerization of a carboxylic acid by formation of hydrogen bonds (shown as dotted lines) When solute particles associate in solution, i is less than 1. For example, carboxylic acids such as acetic acid (ethanoic acid) or benzoic acid form dimers in benzene, so that the number of solute particles is half the number of acid molecules.