{"id":1592,"date":"2018-03-21T15:29:36","date_gmt":"2018-03-21T15:29:36","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-orgbiochemistry\/chapter\/physical-properties-of-esters\/"},"modified":"2018-05-09T16:52:39","modified_gmt":"2018-05-09T16:52:39","slug":"physical-properties-of-esters","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-orgbiochemistry\/chapter\/physical-properties-of-esters\/","title":{"raw":"15.7 Physical Properties of Esters","rendered":"15.7 Physical Properties of Esters"},"content":{"raw":"
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Learning Objectives<\/h3>\r\n
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  1. Compare the boiling points of esters with alcohols of similar molar mass.<\/li>\r\n \t
  2. Compare the solubilities of esters in water with the solubilities of comparable alkanes and alcohols in water.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\nEster molecules are polar but have no hydrogen atom attached directly to an oxygen atom. They are therefore incapable of engaging in intermolecular hydrogen bonding with one another and thus have considerably lower boiling points than their isomeric carboxylic acids counterparts. Because ester molecules can engage in hydrogen bonding with water molecules, however, esters of low molar mass are somewhat soluble in water. Borderline solubility occurs in those molecules that have three to five carbon atoms. <\/span>Table 15.4 \"Physical Properties of Some Esters\"<\/a> lists the physical properties of some common esters.<\/span>\r\n\r\n<\/div>\r\n<\/div>\r\n
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    Note<\/h3>\r\n

    Esters are common solvents. Ethyl acetate is used to extract organic solutes from aqueous solutions\u2014for example, to remove caffeine from coffee. It also is used to remove nail polish and paint. Cellulose nitrate is dissolved in ethyl acetate and butyl acetate to form lacquers. The solvent evaporates as the lacquer \u201cdries,\u201d leaving a thin film on the surface. High boiling esters are used as softeners (plasticizers) for brittle plastics.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n

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    Table 15.4<\/span> Physical Properties of Some Esters<\/th>\r\n<\/tr>\r\n
    Condensed Structural Formula<\/th>\r\nName<\/th>\r\nMolar Mass<\/th>\r\nMelting Point (\u00b0C)<\/th>\r\nBoiling Point (\u00b0C)<\/th>\r\nAroma<\/th>\r\n<\/tr>\r\n<\/thead>\r\n
    HCOOCH3<\/sub><\/td>\r\nmethyl formate<\/td>\r\n60<\/td>\r\n\u221299<\/td>\r\n32<\/td>\r\n<\/td>\r\n<\/tr>\r\n
    HCOOCH2<\/sub>CH3<\/sub><\/td>\r\nethyl formate<\/td>\r\n74<\/td>\r\n\u221280<\/td>\r\n54<\/td>\r\nrum<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>COOCH3<\/sub><\/td>\r\nmethyl acetate<\/td>\r\n74<\/td>\r\n\u221298<\/td>\r\n57<\/td>\r\n<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>COOCH2<\/sub>CH3<\/sub><\/td>\r\nethyl acetate<\/td>\r\n88<\/td>\r\n\u221284<\/td>\r\n77<\/td>\r\n<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>CH2<\/sub>CH2<\/sub>COOCH3<\/sub><\/td>\r\nmethyl butyrate<\/td>\r\n102<\/td>\r\n\u221285<\/td>\r\n102<\/td>\r\napple<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>CH2<\/sub>CH2<\/sub>COOCH2<\/sub>CH3<\/sub><\/td>\r\nethyl butyrate<\/td>\r\n116<\/td>\r\n\u2212101<\/td>\r\n121<\/td>\r\npineapple<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>COO(CH2<\/sub>)4<\/sub>CH3<\/sub><\/td>\r\npentyl acetate<\/td>\r\n130<\/td>\r\n\u221271<\/td>\r\n148<\/td>\r\npear<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>COOCH2<\/sub>CH2<\/sub>CH(CH3<\/sub>)2<\/sub><\/td>\r\nisopentyl acetate<\/td>\r\n130<\/td>\r\n\u221279<\/td>\r\n142<\/td>\r\nbanana<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>COOCH2<\/sub>C6<\/sub>H5<\/sub><\/td>\r\nbenzyl acetate<\/td>\r\n150<\/td>\r\n\u221251<\/td>\r\n215<\/td>\r\njasmine<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>CH2<\/sub>CH2<\/sub>COO(CH2<\/sub>)4<\/sub>CH3<\/sub><\/td>\r\npentyl butyrate<\/td>\r\n158<\/td>\r\n\u221273<\/td>\r\n185<\/td>\r\napricot<\/td>\r\n<\/tr>\r\n
    CH3<\/sub>COO(CH2<\/sub>)7<\/sub>CH3<\/sub><\/td>\r\noctyl acetate<\/td>\r\n172<\/td>\r\n\u221239<\/td>\r\n210<\/td>\r\norange<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n
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    Concept Review Exercises<\/h3>\r\n
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      Which compound has the higher boiling point\u2014CH3<\/sub>CH2<\/sub>CH2<\/sub>CH2<\/sub>OH or CH3<\/sub>COOCH3<\/sub>? Explain.<\/p>\r\n\r\n<\/div><\/li>\r\n \t

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      Which compound is more soluble in water\u2014methyl butyrate or butyric acid? Explain.<\/p>\r\n\r\n<\/div><\/li>\r\n<\/ol>\r\n<\/div>\r\n

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      [reveal-answer q=\"478093\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"478093\"]<\/p>\r\n\r\n

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      1. CH3<\/sub>CH2<\/sub>CH2<\/sub>CH2<\/sub>OH because there is intermolecular hydrogen bonding (There is no intermolecular hydrogen bonding in CH3<\/sub>COOCH3<\/sub>.)<\/li>\r\n \t
      2. butyric acid because of hydrogen bonding with water\u00a0[\/hidden-answer]<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n
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        Key Takeaways<\/h3>\r\n<\/div>\r\n
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