which of the following linear molecules is a nonpolar molecule containing polar bonds?

H-C=N between C and N are three lines
O=C=O
H-Cl
N=N between N and N are three lines

Please explain... I am having a hard time comprephening this stuff.

Thanks

In the NH3 example I gave I called that a trigonal planar molecule; I should have named it a trigonal pyramidal molecule.

To determine if a molecule is nonpolar but contains polar bonds, we first need to understand the concept of polarity.

A polar molecule is one in which the electron distribution is uneven, resulting in a partial positive charge on one end of the molecule and a partial negative charge on the other end. This polarity can be due to differences in electronegativity (the ability of an atom to attract electrons) between the bonded atoms.

Now let's analyze each of the given linear molecules:

1. H-C=N (between C and N are three lines): This molecule is known as hydrogen cyanide (HCN). It contains polar bonds because nitrogen (N) is more electronegative than carbon (C). However, it is also a polar molecule since HCN has a bent shape due to a lone pair of electron on the nitrogen atom. This causes an uneven distribution of electron density and gives rise to a partial negative charge on the nitrogen side and a partial positive charge on the hydrogen side.

2. O=C=O: This molecule is carbon dioxide (CO2). Carbon and oxygen have electronegativity differences, and thus, the carbon-oxygen bonds are polar. However, CO2 is a linear molecule with a symmetrical distribution of polar bonds. This symmetry cancels out the individual bond polarities, resulting in a nonpolar molecule.

3. H-Cl: This molecule is hydrogen chloride (HCl). Hydrogen and chlorine have an electronegativity difference, making the bond polar. However, HCl is a linear molecule with a dipole moment toward the chlorine atom. Thus, it is a polar molecule.

4. N=N (between N and N are three lines): This molecule is dinitrogen (N2). Nitrogen has the same electronegativity, so the N-N bond is nonpolar. In addition to that, N2 is a linear molecule with symmetrical bonding, which cancels out any polarity that could exist, making it a nonpolar molecule.

So, the linear molecule that is nonpolar but contains polar bonds is carbon dioxide (O=C=O).

To determine whether a molecule is polar or nonpolar, we need to consider both the molecular geometry and the presence of polar bonds.

First, let's discuss the concept of molecular geometry. Molecular geometry refers to the arrangement of atoms in a molecule, taking into account the bond angles and the positions of the atoms in three-dimensional space. It helps determine the overall shape of the molecule.

Next, let's discuss polar bonds. Polar bonds occur when there is an unequal sharing of electrons between two atoms in a chemical bond. This can happen when one atom has a higher electronegativity (the ability to attract electrons) than the other atom in the bond. The unequal distribution of electrons creates a separation of charge, resulting in a positive and a negative end of the bond.

Now, let's analyze the given linear molecules:

1. H-C=N: In this molecule, the bond between C and N is triple (three lines). Nitrogen (N) is more electronegative than carbon (C), so the bond is polar. However, since this molecule is linear, the polar bonds cancel each other out, resulting in a nonpolar molecule overall.

2. O=C=O: This molecule is known as carbon dioxide (CO2). The bond between C and each O is double (two lines). Oxygen (O) is more electronegative than carbon (C), so the C=O bonds are polar. However, the molecule is linear, and the two polar bonds are arranged symmetrically across the central carbon atom. As a result, the bond polarities cancel out, making the overall molecule nonpolar.

3. H-Cl: This molecule is hydrogen chloride (HCl). The bond between H and Cl is a single bond. Chlorine (Cl) is more electronegative than hydrogen (H), so the bond is polar. Since this molecule is not linear, the overall molecule is also polar.

4. N=N: This molecule is dinitrogen (N2), where both nitrogen atoms are connected by a triple bond (three lines). Nitrogen (N) has a similar electronegativity, so the bond is nonpolar. Additionally, the linear arrangement of the atoms does not allow for any polar bonds. Therefore, the molecule is nonpolar.

To summarize, out of the given linear molecules, only the molecule H-Cl is a nonpolar molecule containing polar bonds. The other molecules either have no polar bonds or their polar bonds are canceled out due to the linear arrangement.

To be polar you must have these TWO items (both of them). Just one won't do.

a. You must have polar bonds meaning that the two atoms must have different electronegatives.
b. The molecule must NOT be symmetrical (in 3D space).
For example, CH4 has polar bonds because the electronegativity (EN) of C is 2.5 and that of H is 2.1 so there is a SLIGHT polarity and that satisfies #1.
But #2 is not satisfied because CH4 is a tetrahedral molecule so the polarity of the four individual polarized bonds is off set.

BUT look at CH3Cl. Each C-H bonds is polar; the C-Cl bond is polar but not the same as the C-H bonds. The molecule is tetrahedral but because one bond is different (the C-Cl bond) this molecule as a whole is polar.

Another example. CH4 vs NH3
CH4 is not polar for the reasons outlined above. What about NH3?
Each N-H bond is polar because EN for N is about 3 and H is 2.1 However, when you look at the NH3 molecule it is trigonal planar with those two unpaired electrons sitting on top. See this.
https://www.google.com/search?q=molecular+structure+NH3&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb
That is a non-symmetrical molecule so it satisfies both 1 and 2 and it is polar.
In your question, all of the molecules are linear. It tells you that in the question.
HCN the delta EN for C-H is not the same as the delta EN for C-N so those two polar bonds (in opposite directions) don't cancel and the molecule is polar.
CO2. The left C-O bonds is polar; the right C-O bond is polar and the exact polar bonds in exactly opposite directions cancel so CP2 is not a polar molecule.
N-N can't be polar There is no delta EN.
HCl, of course, is a polar molecule.
Hope this helps. Follow up if this is not clear.