sorry guys.. some AP Chem MC questions

<p>here goes.. thanks for the help = )</p>

<h1>1 Given the following chlorine-containing compounds: BrCl, Cl2, ICl, LiCl. Arrange these compounds in order of increasing bond polarity.</h1>

<p>A. Cl2<LiCl<ICl<BrCl B. LiCl<BrCl<ICl<Cl2 C. Cl2<BrCl<ICl<LiCl
D. BrCl<ICl<Cl2<LiCl</p>

<h1>2 A molecule has the chemical formula XY3 (3 is a subscript). Y is more electronegative than X. In order for this molecule to be nonpolar, its molecular geometry must be--</h1>

<p>A. triangular planar B. triangular pyramid C. triangular bipyramidal D. T-shaped</p>

<h1>3 The Lewis Structure for AsH3 (subscript 3) predicts:</h1>

<p>A. sp2 hybrid orbitals for the central As atom
B. a total of ten valence electrons
C. a triangular pyramid molecular geometry
D. a molecule without a dipole moment
(For this one, i think she said all are wrong so we have to make A,B,C,D, true?)</p>

<h1>4-- last one :)</h1>

<p>One molecule that does NOT possess an octect of electrons around the central atom would be
A. CO2 B. NO2 C. SO2 D. SiO2</p>

<p>Thanks!!!</p>

<ol>
<li>A</li>
<li>A</li>
<li>they are all wrong and I dont understand what your teacher is saying</li>
<li>B</li>
</ol>

<p>???</p>

<p>for number one...i dont think its A....isnt Br- a bigger anion than I- thus causing it to have a greater dipole moment</p>

<p>uhh yeah i agree with mine is different...
i would say Cl2, ICl, LiCl, BrCl.</p>

<p>Chloride with Iodide would have less polarity than with Lithium. Lithium is farther away, but it all depends on electronegativity values (which i don't know off the top of my head!)</p>

<p>ok yeah just looked it up (electro #'s)... Chlorine is 3.0, Lithium is 1.0 Iodide is 2.5. the difference between Cl and Li is 2 and the diff from I to Cl is .5.</p>

<p>2>.5 so LiCl has to be more polar than ICl.</p>

<p>or just look at it this way... salts (metal + non-metal) like LiCl have higher polarities than covalent (just non-metal) compounds like ICl.</p>

<p>or you can just put down A and get it right, with no protest.</p>

<p>wait a sec... for #3, isn't C right?</p>

<p>i just jotted a lewis for ash3 and got this...
| . .
H : As : H
| . .
| H
(bars are there for spacing...)</p>

<p>wouldn't it be triangular pyramidal, with a dipole moment going irectly down the center, between all the hydrogens??</p>

<p>Actually Arsenic would have 2 lone pairs (T-Shaped)</p>