During the hydrogenation of vegetable oil, a nickel catalyst is used at 200°C. What happens to the carbon-carbon double bonds in the unsaturated fatty acid chains?

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Question

During the hydrogenation of vegetable oil, a nickel catalyst is used at 200°C. What happens to the carbon-carbon double bonds in the unsaturated fatty acid chains?

Accepted Answer

They are converted to carbon-carbon single bonds — Award 1 mark for understanding that C=C double bonds are converted to C–C single bonds by addition of hydrogen. A is incorrect — the chain length remains the same. C is incorrect — no oxidation occurs. D is incorrect — the chain structure remains unbranched.

Answer

They are broken and the chain length decreases

Answer

They are converted to carbon-oxygen double bonds

Answer

They are converted to carbon-carbon single bonds

Answer

They remain unchanged but the chain becomes branched

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