Write the Lewis structure for nitrosyl chloride, CINO. Using only a periodic table, identify: (a

Write the Lewis structure for nitrosyl chloride, CINO. Using...

Key Concepts

Lewis Structure

The Lewis structure is a diagrammatic method to represent the atoms, bonds, and lone pair electrons in a molecule. It provides insight into how atoms in a compound share or transfer electrons, which is crucial for predicting molecular geometry, reactivity, and the types of bonds (single, double, triple) present.

Valence Electrons

Valence electrons are the electrons found in the outermost electron shell of an atom. They play a major role in chemical bonding and are deduced by using the periodic table. Counting these electrons accurately is essential for constructing a correct Lewis structure and understanding how atoms bond.

Bond Order and Bond Strength

Bond order refers to the number of chemical bonds present between a pair of atoms. A higher bond order typically implies that the bond is shorter and stronger because of more extensive electron sharing. This concept is key to evaluating which bond in a molecule may be the strongest based on its structure.

Bond Length

Bond length is the distance between the nuclei of two bonded atoms. It is influenced by the number of shared electrons (bond order) and the atomic radii of the atoms involved. In a molecular structure, the longest bond is usually associated with a lower bond order or larger atomic sizes.

Electronegativity and Bond Polarity

Electronegativity is a measure of an atom's ability to attract electrons towards itself when forming chemical bonds. Differences in electronegativity between two atoms lead to bond polarity, where a substantial difference results in a highly polar bond. This concept is crucial for determining the most polar bond within a molecule.

Transcript

00:01 Nitrosyl chloride is what we're drawing the lewis structure for.

00:06 A cl -n -o.

00:07 And i've got a periodic table -up that shows the valence electrons for each element.

00:12 So we'll start by adding up our valence electrons.

00:15 A chlorine has seven, nitrogen has five, and then our oxygen has six, for a total of 18 valence electrons.

00:31 Now, if you struggle with how to connect these up, meaning who's going to go in the middle.

00:36 There's a general trend that the first element written in the formula goes in the middle, but that's actually not in the case.

00:44 That's your central atom.

00:45 That's actually not the case here.

00:46 And so a fallback that works pretty much every time, except hydrogen, but pretty much every other time, whoever is the least electronegative goes in the middle.

00:58 The outer electrons or the outer atoms tend to be very electron rich.

01:02 They tend to have more electron like loan pairs and things.

01:05 And so they tend to be the more electronegative atoms.

01:09 So the one in the middle will be the least electronegative.

01:12 Now, electronegativity increases as you go up into the right, maxing out at fluorine.

01:17 So we're really looking to see who's the closest to fluorine.

01:22 Or who's, i guess if we don't want to be electronegative, who's the farthest from fluorine, which is nitrogen in this case.

01:28 Here's fluorine.

01:29 Nitrogen is two steps away.

01:30 Plurine is right next door.

01:32 So we're going to put nitrogen in the middle.

01:34 Put a cl, i don't know.

01:39 Now tracking electrons as we go.

01:41 Two bonds, two electrons each.

01:44 We've used four electrons so far.

01:47 We've got 14 more to go.

01:49 We want to fill up our outer electrons before we worry about our inner ones.

01:54 So each of these needs six more.

01:59 That cuts us down to 12.

02:03 We've got two left.

02:05 That'll go on the nitrogen.

02:07 Now that nitrogen does not have a full octet yet.

02:13 It only has six electrons.

02:15 So we've got to do a double bond, and we have a choice.

02:20 We can either take it from the chlorine, or we could take it from the oxygen.

02:28 Now we're going to have to check each option and see who has the better set of formal charges.

02:33 So our two options are going to be cl, double bond, n, o, which would look like this, or the double bond would be on the other side, and it'd look like this.

02:59 Quick reminder that formal charge of an atom looks a lot like just a normal charge, but it depends on the molecule.

03:10 It equals the number of valence electrons that an element starts with minus half of its bonding electrons for that element, and all of its non -bonding electrons.

03:24 A quicker way to memorize this is it's the valance electrons minus how many sticks are attached to that atom, minus how many dots are on that atom.

03:42 All right.

03:43 So looking at our first one here.

03:47 Chlorine has starting with seven valence just from the periodic table.

03:53 Remember it's from this column.

03:54 That's a seven.

03:55 Okay.

03:56 Minus there are two sticks attached to that chlorine and there are four dots on it.

04:02 So that gives you a formal charge of plus 1.

04:08 Zero would be better, but we'll go with what we've got for now.

04:12 Next, we've got nitrogen.

04:14 Nitrogen starts with five valence, just based on the periodic table...