Dipole Moment (Simplified) - Video Tutorials & Practice Problems

Dipole Moment (Simplified) Concept 1

Now, before we can talk about dipole moments, we have to take a look at electoral negativity. We're going to say it's the measurement of an element's ability to attract electrons to itself. So basically the higher electro negativity value as an element, the more you desire electrons near you, We're gonna say 1932. It was the American chemist Linus Pauling who proposed electro negativity values for the elements. I thought this was good to include because at this point we've heard a lot about chemist from Germany, from Russia, from France. We don't usually hear too much about old school chemists from the U. S. Here. We're going to say that the periodic trend of electro negativity is as removing from left or two right across a period and going up a group. Our electro negativity should increase. So electro negativity increases in this movement. And we're gonna say, as we head towards the top right, basically are electro negativity is increasing. Now, remember we said that electro negativity is the elements ability to attract electrons to itself. The noble gases are perfect. They don't really want electrons. Of course there are exceptions to this in the form of krypton and xenon. They exist in the sweet spot of group ate a where they could accompany additional electrons to themselves to help make different types of lewis dot structures. But what's most important in this graph is that flooring is the most electoral negative. Easy way to remember that is in college. We're all looking for that. Perfect 4.0, flooring is 4.0 in terms of electro negativity. Okay, so as we head towards flooring things become more and more electoral negative. All right. So this is the basic trend that you need to keep in mind when talking about electro negativity as a periodic trend

Dipole Moment (Simplified) Example 1

here, It says which of the following represents the most electro negative alkaline earth metal. All right, so this question is actually easier than it appears. You don't need to look at the electro negative values you don't even need toe. Remember the pattern because there's only one alkaline earth metal presented here. The only element that's an outline. Earth metal is beryllium. So the answer here is deep. But remember, the general trend is, as we head to the top right corner of the periodic table are electro negativity will increase. So just keep in mind this general periodic trend for electro negativity.

Dipole Moment (Simplified) Concept 2

now, a dipole moment is the polarity that arises when elements in a bond have a significant difference in their electoral negativity. Not polarity is just the unequal sharing of electrons between these bonding atoms at a difference in electro negativity, greater than four is considered significant now. Difference in electro negativity, which is Delta e n equals the higher electro negativity value minus the lower white. Now, if you have polarity in a bond, you have a dipole moment. This is illustrated by a die poll arrow that always points towards the Mawr electro negative element. If you were to calculate the difference between flooring and carbon, you would see the difference is greater than 0.4. So it has a dipole moment. So we use a depot era here. The end that is more electoral negative gets a partial charge of Delta Negative. The end that is mawr less electro negative. Is Delta positive? If you look at this select type own arrow, you're going to see circling this end, it looks like a positive sign which meat makes sense because this end is partially positive. So remember, if you're difference in electro negativity is significant, you show a depot era. That diaper arrow is representative of the polarity. Within that bond, the end where the diaper arrow is pointing will be partially negative, and the other end will be partially positive.

Dipole Moment (Simplified) Example 2

Calculate the difference in electro negativity values between carbon and flooring. So here we still have the image of carbon connected to flooring. We have the presence of a depot area because the difference between them should be greater than .4. Now let's complete what exactly the value is On our periodic table. The electro negativity value of flooring is four And that of carbon is 2.5. So here we're gonna say difference and electro negativity equals the higher electro negativity value in this case 4.0 - the smaller one of 2.5. When we do that, we get a difference of 1.5 which is option deep. And again, since the difference exceeds .4, we know that this compound has a dipole moment. And as a result we use a depot arrow to illustrate that. Remember the depo arrow itself points towards the more electro negative element within the bond.

Arrange the following molecules in order of decreasing dipole moment.

H–I           H–F         H–Br         H–Cl

• A. H–Cl >H–I > H–Br > H–F
• B. H–Br >H–Cl > H–F > H–I
• C. H–F >H–Cl > H–Br > H–I
• D. H–I >H–Cl > H–Br > H–F

Dipole Moment (Simplified) Concept 3

we're going to say that the difference and electro negativity ease between two elements can determine the type of chemical bond present we're going to say the greater the difference in electoral negativity in the greater the polarity of the bond. Now, if we take a look, we can see here that we have differences and electro negativity ease. If the difference is zero, that must mean they both have the same electro negativity value. We classify this as a pure Covalin Bond. Great example is too, bro means bonded together. They're sharing these electrons here in the center, and they're sharing them equally. So you have these equal arrows between them. Here. This shading represents their electron cloud their equal in size because again they're electro negative. Values are the same. They're sharing them perfectly. Now, once you start getting a little bit difference in electro negativity, we go into what we call a non polar Covalin bond. Here it has a difference between 0.1 and 0.4. If we take a look here. Carbon is slightly bigger in terms of its electron cloud because it's electro negative. Value is a little bit higher than hydrogen. It's 2.5 versus hydrogen is 2.1. We still have arrows, but notice that this arrow is slightly larger because the electrons belong a little bit more towards carbon side. Now, what you need to realize here is that pure Covalin is when there is no difference in electro negativity. But it is also classified as being non polar. Now, intermediate is when the differences between 0.5 and 1.7. Here we classify this as a polar Covalin bond. If we take a look here, we have chlorine and hydrogen, Remember, once were greater than 0.4 difference in electro negativity. That's significant. That means we're gonna be polar and with a polarity involved, we have dipole arrows. The dipole arrow always points towards theme or electro negative element. It's pointing towards cart on chlorine, which is more electro negative than hydrogen. Remember, chlorine is 30 Hydrogen is just 2.1. With the depo era. We have charges involved in this case, partial charges here. Corn will be partially negative. Hydrogen will be partially positive. Finally, if it's larger than 1.7 than it is an Ionic bond. Remember, Ionic bonds are bonds between a positive ion and a negative ion here. The difference is so large that the cat eye on his form because sodium actually hands over its electron to chlorine. Now here it also has a depot arrow. But it's much larger because the polarity is even greater here. This is another difference. Here is that whereas in polar Covalin we have partial charges in Ionic we have full charges, so this is fully negative and this is fully positive. And again, the arrow points towards the mawr electro negative element. So just remember the greater difference in electro negativity, the greater the polarity of the bond. These differences in polarity helped to classify different types of chemical bonds present.

Dipole Moment (Simplified) Example 3

for those listed below, which has the most polar bond. Remember, the most polar bond would be attached to the greatest difference and electro negativity. Looking at the electoral negativity is chart. We'd see that sulfur is 2.5. Selenium is 2.4. We'd see here to five. Hydrogen would be to one chlorine. Here would be three point. Oh, and here we have flooring at four point out sulfur again is to five and four inches. 40 This would be 2.5, and this would be 3.5. Remember, difference in electro negativity is the larger electro negativity value minus a smaller one. Here. If we did that before minus 2.5, which would give us 1.5. We see that option D gives us the biggest difference in electro negativity, which would translate into the most polar bond present. So just remember, most polar bond means biggest difference in electro negativity is

Which of the following correctly identifies the chemical bond between a carbon and oxygen atom?

a) Polar Covalent

b) Pure Covalent

c) Nonpolar 

d) Ionic

• A. Polar Covalent
• B. Pure Covalent
• C. Nonpolar
• D. Ionic

Between which two elements is the difference in electronegativity the greatest?

• A. C and Si
• B. Li and I
• C. Na and P
• D. K and F
• E. Br and Cl

Which of the following correctly identifies the chemical bond between two bromine atoms?

• A. Polar Covalent
• B. Pure Covalent
• C. Nonpolar Covalent
• D. Ionic