Question

!. Which of the following structures would you expect to have a net dipole moment?

HC(triple bond)CH
NH4+
H2C(double bond)O
BCl3

2. Rank the sp, sp2, and sp3 orbitals in order of decreasing (highest to lowest) energy.

a)sp> sp2>sp3
b)sp3>sp2>sp
c)sp2>sp>sp3
d)they are all the same

Answer 1

i believe H2C O with the double bond is the only one with a dipole moment

Answer 2

HCtriplebondCH is linear and no dipole moment.
NH4^+ is tetrahedral and symetrical; therefore, no dipole moment.
H2C=O is not symmetrical in three dimensions; it has as dipole moment.
Same for BCl3.
For #2. here is come good reading.
http://chemwiki.ucdavis.edu/Organic_Chemistry/Fundamentals/Hybrid_Orbitals

Answer 3

i got the first one easy enough. the reading was interesting. so that leads me to believe b is the correct answer. thank you dr. bob