Without consulting Table 2.5, arrange the following compounds in order of decreasing heat of combustion: pentane, isopentane, neopentane, hexane.

Transcribed Image Text:

TABLE 2.5 Heats of Combustion (-AH) of Representative Alkanes Compound Formula kJ/mol kcal/mol Unbranched alkanes Hexane Heptane Octane Nonane Decane Undecane Dodecane Hexadecane CH3(CH2)4CHa CH3(CH2)5CH3 CH3(CH26CH3 CH3(CH2)CHa CH3(CH2)8CH3 CH3(CH2)9CH3 CH3(CH2)10CH3 CH3(CH2)14CH3 4,163 4,817 5,471 6,125 6,778 7,431 8,086 10,701 995.0 1151.3 1307.5 1463.9 1620.1 1776.1 1932.7 2557.6 2-Methyl-branched alkanes 2-Methylpentane 2-Methylhexane 2-Methylheptane (CH3)2CHCH2CH2CHa (CH3)2CH(CH2)aCH3 (CH3)2CH(CH2)4CH3 4, 157 4,812 5,466 993.6 1150.0 1306.3