Draw Lewis structures for the following compounds, and predict which member of each pair will fo

step 1 All right, hi, everyone. Today we're going to be looking at designing, drawing out some Lewis do

Draw Lewis structures for the following compounds, and...

Key Concepts

Molecular Geometry and Polarity

Molecular geometry refers to the three-dimensional arrangement of atoms in a molecule, while polarity describes the distribution of electrical charge within the molecule. Together, these concepts help predict the physical properties of substances, as the shape and electron distribution influence the ability of molecules to engage in intermolecular interactions like hydrogen bonding.

Electronegativity

Electronegativity is the tendency of an atom to attract shared electrons in a chemical bond. Differences in electronegativity between atoms lead to the formation of polar bonds, which are crucial for determining molecular polarity and the strength of intermolecular interactions such as hydrogen bonding.

Lewis Structures

Lewis structures are diagrams that represent the valence electrons of atoms within a molecule, showing how atoms are bonded together and where lone pairs of electrons are located. They provide insight into the connectivity and potential reactivity of a molecule by illustrating the arrangement of electrons around atoms and can help predict molecular geometry and polarity.

Hydrogen Bonding

Hydrogen bonding is a specific type of dipole-dipole attraction that occurs when hydrogen is covalently bonded to a highly electronegative atom, such as nitrogen, oxygen, or fluorine. This bond creates a partial positive charge on the hydrogen, which can then interact with lone pairs on electronegative atoms in neighboring molecules, influencing boiling points and solubility.

Transcript

00:02 All right, hi, everyone.

00:03 Today we're going to be looking at designing, drawing out some lewis dot structures, and then using that information to try to determine if certain compounds will form hydrogen bonds or if they would not likely form hydrogen bonds.

00:18 So we're going to start today with two different compounds.

00:22 We'll start with nitrogen tri -fluoride.

00:27 Who is nf3.

00:30 And we're going to compare that to ammonia, which is nh3.

00:36 So before i start lewis dot structures, especially if it's been a while since i've created one, i like to remind myself of the needs of each of the atoms that we're talking about here.

00:46 So in the case of nitrogen, nitrogen has five valence electrons.

00:52 So when we're creating kind of a reference point, we've got our first four that we fill in, and then we start going back around.

00:59 And for nitrogen, we're just going to have one more electron to identify in the top.

01:07 And so we can see here that nitrogen then has five valence electrons, and it needs three more in order to fill up that entire outer shell.

01:17 Case of fluoride, we are a halogen.

01:21 And so this element is almost full.

01:26 And it requires only one more electron.

01:29 So it has seven electrons in its outermost shell.

01:34 And then when we're looking at hydrogen, hydrogen and helium, those two elements, they only need two electrons to fill their outer most shell.

01:44 And so hydrogen has one valence electron, and it needs one more valence electron.

01:50 So we'll start with the nitrogen trifluoride.

01:54 Nitrogen is going to be our element.

01:56 We'll kind of start in the center here.

01:58 And we already know that with those two are filled at the top.

02:02 This one only needs to have one, three more electrons, which fluoride is willing to offer one or share one.

02:11 And we can indicate that sharing with a straight line.

02:16 And there are three fluorides available.

02:23 So we can indicate that mistastructure as such.

02:28 So fairly straightforward for this one.

02:30 Not a lot to try to figure out or reconstruct.

02:35 And we're going to see something fairly similar for ammonia as well.

02:37 So again, nitrogen still is going to need three more electrons.

02:43 And hydrogen has one that it's willing to share.

02:50 And there are three hydrogens available for ammonia.

02:53 So this is our lewis step structure for ammonia on the right and for nitrogen trifluoride on the left.

03:00 So the next thing we want to think about is which of these two compounds is most likely to form hydrogen bonds.

03:06 A lot of that has to do with whether or not those electrical.

03:12 Are going to be pulled at about the same amount and shared equally, or if one of the elements is going to be pulling those electrons a little bit more strongly.

03:22 Because nitrogen only needs three more electrons to be happy, and hydrogen is really kind of willing to give up that first, that only electron it has.

03:32 Nitrogen is actually going to be pulling the electron from hydrogen just a little more strongly than the hydrogen is going to be pulling the electron from nitrogen.

03:42 And so these hydrogens are going to have just slight negative charges.

03:47 And that slight negative charge is going to be what allows this compound to form hydrogen bonds.

03:53 And so here we'll see that ammonia is most likely to form a hydrogen bond.

03:58 If we compare that to the nitrogen tri -fluoride, fluoride and nitrogen, they're both pulling pretty equally for the electrons that they want.

04:07 And so we're not going to see that discrepancy in terms.

04:12 Of how charge on the outer ends of the element.

04:19 So let's move to a slightly more complicated example...

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