Quiz 2 Flashcards
Lewis and Bronsted Acids + Bases, Arrow Pushing, Ka/pKa/equilibria, Alkene Structure + Stability, Heats of Formation, E/Z Stereoisomers + Priority System, and H-X Addition to Stereoisomers (17 cards)
What is the periodic trend for bronsted acidity?
Down the periodic table and left to right, acidity increases
What is the effect of charge on bronsted acids?
Charged molecule. more likely to accept incoming electron pair
What is the effect of resonance on bronsted acids?
More resonance = more stability and thus more acidity
How do bond inductive effects affect bronsted acids?
Polar covalent bonds have bond inductive effects. Inductive effects are cumulative, and they fall off rapidly with distance
What is the difference between constitutional and stereoisomers
Constitutional isomers refer to 2 different molecules with the same formula but different connectivity, while stereoisomers are molecules with the same molecular formula and connectivity but different 3D arrangement that cant be superimposed on each other
How does E-Z nomenclature of alkenes work?
Assigns priority to groups in each carbon atom of double bond. E = opposite, z = together
What are the rules for assigning priority to alkenes?
Higher atomic # is higher priority, higher atomic mass then, and if connecting atoms same, work outwards to 1st point of difference
What is the relationship between heat of formation and alkene stability?
Lower heat of formation is lowest in energy, and most stable
What is stronger: a sigma bond between two sp2 orbitals or two sp3 orbitals?
Two sp2 orbitals. Shorter and stronger than sp3-sp3
What is an amphoteric compound?
Chemicals that can act as both an acid or a base
Difference between lewis and bronsted lowry acids/bases?
Lewis acids are electron acceptors (bases donors). Bronsted acids are proton donors (bases acceptors)
How does H-X addition to alkenes work?
The alkene’s pi (double) bond breaks.
The electrophilic H forms a new sigma (single) bond with the alkene.
The halide adds to the carbocation.
How does Ka relate to acid strength?
Higher Ka = stronger acid
How does pKa relate to acid strength?
Lower pKa = stronger acid
What are some rules to determining lewis acid/bases?
Metal cations (like Fe3+) accept electrons and are acids. Molecules with electron deficient central atoms (like AlCl3) can accept electrons and are acids]
Molecules with polar double bonds (like SO3) accept electrons and are acids
atoms with an excess of electrons, such as anions (I-) or molecules with lone pair electrons (NH3), can donate electrons
