These kinds of questions are easiest to answer if you have an electronegativity table and a molecular model kit handy. In order for a molecule to have a permanent dipole (as opposed to the transient dispoles produced by lesser forces like London Dispersion) you need a bond between two or more atoms with a significant electronegativity difference, and a three dimensional structure that allows one or both of the atoms involved in the dipole to be accessible from the outside of the molecule in a "lopsided" manner (in contrast, dipole atoms that are uniformly arranged can effectively cancel the dipole by not having an accessible charge difference from the outside).
a: the C-Cl bond would be a good candidate for a dipole, but this molecule has a tetrahedral configuration, so that only the negatively charged chlorine are accessible from the outside. This cancels the effective dipole, as mentioned above, so CCl4 is not considered a dipolar.
b:CH2Cl2 makes the two dipolar bonds a little more accessible, but in a linear arrangement, which once again shields the positively charged carbon with the help of the hydrogens. This molecule would be a little more dipolar in nature, but not much.
c: H2O is an ideal model of a dipolar molecule: the O-H bond is highly polar, and the molecule has a bent linear configuration because of the two lone pairs on the oxygen. This makes both of the positive charges on the hydrogen, as well as the negative charge on the oxygen, fully accessible.
d:The answer for HCl may change depending on who you ask; a lot of introductory approaches treat hydrohalics as ionic compounds, and according to this you would say that they aren't polar (although again, depending on who you ask, ionic bonds could be considered an extreme form of polarity). However, HCl is actually covalent: there's a variety of evidences for this, but essentially it means that HCl is a dipole as well. On the other hand, if your instructor is asking for only one answer, I would go with H2O
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