OCR A Jan 2011 Paper 4 Q2

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2 Esters of fatty acids are used as biodiesels. These esters can be produced from triglycerides by the transesterification process below. R' R' R' 3 ROH NaOH catalyst heat R' O R HO HO OH triglyceride biodiesel glycerol (a) Give the systematic name of glycerol.[1] (b) (i) Suggest a suitable alcohol, ROH, that could be used industrially to make biodiesel. Justify your answer.[1] (ii) The alcohol, ROH, is added in excess. Suggest why the alcohol has to be in excess.[1]OCR 2011<br />
 (c) Esters can also be made by reacting an alcohol with either a carboxylic acid or with an acid anhydride. Write equations for the formation of ethyl propanoate, CH3CH2COOCH2CH3, starting from: a carboxylic acid and an alcohol, an acid anhydride and an alcohol. (d) Compound A, C4H8O3, can lose water to form either: compound B, a cyclic ester OR compound C, a polyester. Identify compounds A, B and C. [2] compound A compound B compound C [3] [Total: 8] Turn overOCR 2011<br />

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