0
$\begingroup$

phosphorus oxyiodide ($\ce{POI}$) has the VSPER AXE formula of $\ce{AX2E}$ while water, $\ce{H2O}$ has the AXE code of $\ce{AX2E2}$. According to my work sheet $\ce{POI}$ should have a $120^\circ$ bond angle while $\ce{H2O}$ should have a bond angle of $104.5^\circ$.

Does this mean that due to the extra lone pair it creates less resistance resulting in a greater angle? Also, does it having three different elements in the equation do anything?

Improve this question
$\endgroup$
3
  • $\begingroup$ You mean the molecule O=P–I? Because to me, italicised $POI$ sounds like... a triangle, in geometry. $\endgroup$
    – orthocresol
    Oct 9, 2018 at 23:19
  • $\begingroup$ The worksheet says $POI$ multiple times. In those exact words. I can't seem to find it on the internet. Either there is a mistake (which was repeated multiple times) or it is made up to prove a point? $\endgroup$
    – Zebert
    Oct 9, 2018 at 23:26
  • 1
    $\begingroup$ Well, I'm pretty sure the molecule doesn't exist. But it does fit into the VSEPR scheme of $\mathrm{AX_2E}$, which is why I suspected it was that. And if your only goal is to learn how to apply VSEPR theory, it doesn't particularly matter whether the compound exists or not; you just need to be aware of what you are saying, i.e. "if this molecule existed, VSEPR would predict a bond angle of x degrees" and not "this molecule has a bond angle of x degrees". $\endgroup$
    – orthocresol
    Oct 9, 2018 at 23:28

1 Answer 1

Reset to default
1
$\begingroup$

Does this mean that:

Due to the extra lone pair $\color{red}{\text{it}}$ $\color{limegreen}{\text{creates less resistance}}$ resulting in $\color{blue}{\text{a greater angle}}$?

More like:

Due to the extra lone pair $\color{red}{\text{in } \ce{H2O} \text{ the pendant atoms}}$ $\color{limegreen}{\text{experience more repulsion}}$ resulting in $\color{blue}{\text{a smaller angle}}$ $\color{magenta}{\text{compared to }\ce{POI}}$?

Also, does it having three different elements in the equation do anything?

No, I think the three different elements in the question were there to evaluate if you were:

  1. estute to the fact that oxygen forms a double bond thus
  2. phosphorous has 1 unbonded pair of electrons (not 2) and
  3. if the double bond would hang you up in obtaining an answer.
Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.