OCR A Jun 2016 Paper 4 Q1

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Answer all the questions. 1 Stearic acid, oleic acid and linoleic acid are examples of naturally occurring fatty acids. Traditional name Structure Systematic name Stearic acid Oleic acid C17H35COOH C17H33COOH Octadecanoic acid Octadec-9-enoic acid Linoleic acid C17H31COOH Octadeca-9,12-dienoic acid (a) Suggest which fatty acid in the table is most likely to be linked with concerns about heart disease and obesity. Explain your choice.[1] (b) Sodium stearate is the salt formed when stearic acid reacts with sodium hydroxide solution. Write an equation for the formation of sodium stearate.[1] (c) A triglyceride formed from stearic acid can be found in some types of food. Draw the structure of this triglyceride with any functional groups fully displayed. [2]OCR 2016<br />
 (d) Partial hydrogenation of linoleic acid may result in the formation of trans-octadec-12-enoic acid. (i) Draw the skeletal formula of trans-octadec-12-enoic acid. [2] (ii) Some fatty acids show cis-trans isomerism because there is restricted rotation about a C=C double bond. State one other feature of these molecules that enables them to show cis-trans isomerism.[1] [Total: 7]OCR 2016 Turn over<br />

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