CH2-OOC-R CH2OH
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CH-OOC-R + 3NaOH → CHOH + 3RCOONa
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CH2-OOC-R CH2OH
22.25g ÷ ( 3g ÷ 40g/mol × 1/3 ) = 890g/mol
该饱和脂肪酸甘油酯的相对分子质量为890.
( 890 - 12×6 - 5 - 16×6 ) ÷ 3 = 239,其中饱和脂肪酸的烷基（-CnH2n+1）部分式量为239,14n + 1 = 239,解得：n = 17,这种高级脂肪酸为：C17H35COOH——硬脂酸.