In which hydride is the H-X-H bond angle the smallest?
In which hydride is the H-X-H bond angle the smallest?
A. BH_3
B. CH_4
C. C_2H_6
D.NH_3
In which hydride is the H-X-H bond angle the smallest?
A.
B.
C.
D.
1 Answer
Well, it's not entirely obvious. It is either
CCCBDB gives:
color(blue)(/_"HCH" = 108^@)
http://cccbdb.nist.gov/exp2x.asp?casno=74840
color(blue)(/_"HNH" = 106.67^@)
http://cccbdb.nist.gov/exp2x.asp?casno=7664417
And so, as it turns out, the lone-pair-bonding-pair repulsion in
Well, if you notice, the first three are all ideal geometries. If you don't notice that, consider their Lewis structures and how they have zero lone pairs of electrons on the central atom:
https://upload.wikimedia.org/
120^@ angle, trigonal planar
https://upload.wikimedia.org/
109.5^@ angle, tetrahedral
Here's where we run into some trouble.
https://encrypted-tbn0.gstatic.com/
109.5^@ predicted, and we get111.17^@ for the"H"-"C"-"C" bond angle, which got bigger.
This is likely due to the
Using conceptual math, an increase of
This predicts roughly
On the other hand,
http://www.chemtube3d.com/
This image suggests a bond angle of