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Hydrates quiz

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  • What type of molecule is formed when water reacts with a carbonyl group?
    A hydrate, specifically a geminal diol, is formed when water reacts with a carbonyl group.
  • What is a geminal diol?
    A geminal diol is a molecule where two hydroxyl groups are attached to the same carbon atom.
  • What initiates the reaction between water and a carbonyl group?
    The lone pairs on the oxygen atom of water attack the electrophilic carbon of the carbonyl group.
  • What intermediate is formed during the reaction of water with a carbonyl?
    A tetrahedral intermediate is formed during the reaction.
  • What happens after the tetrahedral intermediate is formed in hydrate formation?
    A proton transfer occurs, where an oxygen atom grabs a hydrogen from another part of the intermediate.
  • Why is the oxygen from water positively charged in the intermediate?
    It is positively charged because it has gained an extra bond after attacking the carbonyl carbon.
  • What is formalin and how is it formed?
    Formalin is the hydrate formed from formaldehyde reacting with water.
  • What is responsible for the smell in preserved biological specimens?
    Formalin, not formaldehyde, is responsible for the characteristic smell in preserved specimens.
  • Why is hydrate formation not synthetically useful for larger carbonyl compounds?
    Steric hindrance from large R groups makes the tetrahedral intermediate less favorable, shifting equilibrium toward the carbonyl.
  • How does the size of R groups affect hydrate formation equilibrium?
    Larger R groups shift the equilibrium toward the original carbonyl, while smaller R groups favor hydrate formation.
  • Which carbonyl compound is most likely to form a hydrate in equilibrium?
    Formaldehyde, due to its small size and minimal steric hindrance, is most likely to form a hydrate.
  • What happens when you mix a 50% solution of 2-butanone with water in the lab?
    Some of the mixture will form a hydrate, altering the expected composition.
  • What is the main step called when an oxygen atom grabs a hydrogen during hydrate formation?
    This step is called a proton transfer.
  • Why do larger carbonyl compounds rarely form hydrates?
    Because steric hindrance makes the tetrahedral intermediate less stable, favoring the carbonyl form.
  • What is the predominant product when formaldehyde reacts with water?
    The predominant product is formalin, the hydrate form, due to minimal steric hindrance.