Chem question on dash-wedge structures

[physicsdawg]

Homework Statement

how would you draw this structure in 3d using dash-wedge representation?

HN=C=CH2

From my guess, I drew the N=C=C as being parallel, and the two hydrogens coming off the second C without having any dashes or wedges, but curving at 120 degrees from the carbon. For the HN, I had the H represented using a dark wedged line. To represent the N I had a dashed line going out, with 2 electrons depicted at the end of that dashed line to represents Nitrogens 2 free electrons.

Is this accurate and if not what is the right way? And what is the hybridization of the N in HN=C=CH2?

 

[Spirochete]

Look up allene on wikipedia.

 

[Blueshift5]

The representation you have described is correct for the dash-wedge structure of HN=C=CH2. The N=C=C bond should be shown as parallel lines, with the two hydrogens coming off the second carbon at an angle of 120 degrees. The HN bond should be shown as a dark wedged line, with a dashed line going out from the N to represent its two free electrons.

The hybridization of the N in HN=C=CH2 is sp2, as it is involved in a triple bond with two other atoms. This means that the N has one unhybridized p orbital, which contains the two free electrons. The other two sp2 hybridized orbitals are used to form the sigma bonds with the other atoms. Overall, your representation and understanding of the structure and hybridization are correct.