Chemistry question

[NubianPrincess]

I'm trying to figure out the molecular geometry of formic acid, HCOOH. Im thinking that it would be tetrahedral with C as the central atom, but the fact that the molecule is in acid makes me think im wrong. Can anyone help me? <img src="confused.gif" border="0">

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[THE instiGATOR]

Would it not be planar?

O=(CH)-OH

Only three ligands with no valence electrons.

 

[ussdfiant]

Can't be tetrahedral because of the double bonded O. Trigonal planer? God, after April 21, 2001 I forgot all of this stuff.

 

[watto]

sp2, trigonal planar

 

[Coalboy]

Definitely planar.

 

[Sm00th13]

I agree also, trigonal planar, sp2 <img src="graemlins/pissy.gif" border="0" alt="[Pissy]" /> The Instant Graemlins are pretty cool!!!

 

[sundevil1]

one more vote for trigonal planar, but not all bond angles will be equal due repulsion between the unpaired electrons on the oxygens. the oxygen-oxygen bond angle will be &gt;120, the others will be a little less. I don't think the effect will be too great though because of the double bond.

 

[DrBlueDevil]

trigonal planar up in this

 

[Maple]

All I have to say is: <img src="graemlins/wowie.gif" border="0" alt="[Wowie]" />

 

[Tweetie_bird]

Carbon is sp2 hybridized, so it's trigonal planar with the c=o, c-h and c-o
however, the "OH" group is bent due to electron repulsion of the second oxygen that is not double bonded to the Carbon.

Hope it helps.
Tweetie

 

[MorningLight2100]

It's trigonal planar. If you're not wholly convinced, trying drawing out the Lewis structures of each atom; the valences should give you a clue when you consider the octet rule. As sundevil said though, the bond angles will not quite be 120.

 

[NubianPrincess]

Originally posted by Tweetie_bird:
•Carbon is sp2 hybridized, so it's trigonal planar with the c=o, c-h and c-o
however, the "OH" group is bent due to electron repulsion of the second oxygen that is not double bonded to the Carbon.

Hope it helps.
Tweetie•••

Makes sense
Thanks everyone for your help!