"Is the following species a dipole?"
NH2Cl
I have drawn out the lewis dot structure of the molecule and the electronegativy values I have are
N- 3.0
Cl- 3.0
H- 2.1
I know that the electronegativity difference between N and Cl is 0 and the bond is non polar. In my structure, I have this:
H-N-H
with N being bonded to Cl as well and having a free electron pair. Since both hydrogens are being pulled into N with the same "force" or "attraction" is there still a dipole?
Sorry that my question was confusing
Your description of the bonding is a little confusing but I THINK you have it right. I will summarize here just to make sure.
N is the central atom. It has an unshared pair of electrons. A pair of electrons is shared with each H atom and the Cl atom. That makes 3 shared pairs plus an unshared pair which makes four regions of high electron density and that means a tetrahedral arrangement. So a pair of electrons is at one apex, A Cl atom at another and a H atom at the other two "corners." So it is not symmetrical. If there is ANY difference of electronegativity AND the arrangement is not symmetrical (this one isn't), there is a dipole moment. The NH4+ is symmetrical; therefore, even though H and N don't have the same EN, the symmetry of the ion cancels and there is no dipole moment.
Ok, thank you that clears it up a bit =]
I have another question. If I have the ion, NO3-, and I know that it's a resonance structure with one double bond and two single bonds, is this still non-polar? Or does the double bond affect the polarity?
The double bond doesn't change the polarity. The N is the central atom, with no unshared pairs of electrons. It shares two pair with one O, and a pair with each of the other O atoms. At least that is one resonance structure we can draw. So it has three regions of high electron density (one to double bond O and one each to the other two O atoms). Three regions of high electron density is trigonal planar and that is a symmetrical structure. That gives us N in the center and O at the three corners. So no dipole.
I confirm your answer :)
To summarize, the species NH2Cl is polar due to the difference in electronegativity between nitrogen (N) and chlorine (Cl). On the other hand, the NO3- ion is non-polar because of its symmetrical trigonal planar structure, despite the presence of a double bond.
To determine if a molecule has a dipole, you need to consider the electronegativity difference between its atoms and the molecular geometry.
In the case of NH2Cl, the electronegativity values are:
N - 3.0
H - 2.1
Cl - 3.0
First, draw the Lewis dot structure of the molecule. In this case, the nitrogen atom is the central atom, with two hydrogen atoms and one chlorine atom bonded to it. The Lewis structure is:
H-N-H
|
Cl
Next, determine the molecular geometry. NH2Cl has a tetrahedral geometry, with the nitrogen atom at the center and the four atoms (two hydrogens, one chlorine, and one unshared pair of electrons) at the four corners.
Now, check the electronegativity difference between the nitrogen and chlorine atoms. In this case, the electronegativity difference is 0 (both have an electronegativity of 3.0). Since the electronegativity difference is zero and the molecular geometry is not symmetrical, NH2Cl does have a dipole moment. The molecule is polar.
To summarize, NH2Cl is a polar molecule because of the electronegativity difference between nitrogen and chlorine and the non-symmetrical molecular geometry.