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    Why does t-butanol form t-butyl chloride with concentrated hydrochloric acid but an alkene with concentrated sulfuric acid? The mechanisms look like they can proceed either way.
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    (Original post by Lifeisnice)
    Why does t-butanol form t-butyl chloride with concentrated hydrochloric acid but an alkene with concentrated sulfuric acid? The mechanisms look like they can proceed either way.
    The first part of the mechanism is common to both but..

    Conc sulphuric acid is a good dehydrating agent which pulls the second part of the mechanism to the RHS.
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    (Original post by charco)
    The first part of the mechanism is common to both but..

    Conc sulphuric acid is a good dehydrating agent which pulls the second part of the mechanism to the RHS.
    Why does it act as a base and remove a proton?
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    (Original post by Lifeisnice)
    Why does it act as a base and remove a proton?
    It doesn't.

    RCH2OH + H+ --> RCH2OH2+

    RCH2OH2+ --> RCH2+ + H2O

    RCH2+ --> alkene + H+

    The acids protonate the lone pair on the oxygen of the OH group as the first step.

    The sulphuric acid facilitates the second step as a dehydrating agent.
 
 
 
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