ap chem catalyst ap chem catalyst catalyst questions to do & homework ① based on what we...

AP Chem CatalystAP Chem Catalyst AP Chem CatalystAP Chem CatalystCatalyst QuestionsCatalyst Questions To Do & Homework To Do & Homework

① Based on what we learned so far about periodic trends, what is the most difficult topic so far?

② What was difficult about the homework or problem set?

③ What do you need to do to ensure that your grade goes up?

④ What NEW study skills do I need to incorporate?

① Based on what we learned so far about periodic trends, what is the most difficult topic so far?

② What was difficult about the homework or problem set?

③ What do you need to do to ensure that your grade goes up?

④ What NEW study skills do I need to incorporate?

Homework: Complete the rest of the Problem Set 2.1Check your answers using online answer key.Quiz #8 Monday on LS 2.1-2.2

EVERYONE is required to spend a min of 40 minutes once a week in my class to review notes or problem sets once every two weeks either Thurs or Friday within a study group. Attendance will be recorded.

Homework: Complete the rest of the Problem Set 2.1Check your answers using online answer key.Quiz #8 Monday on LS 2.1-2.2


Please create 5 tabs on your folders where you’re temporarily putting stuff. Organization is very important for when we review in April.

1) Notes 2) Outlines 3) Tests/Quizzes/Study Guides 4) Problem Sets 5) Classwork


1) Notes 2) Outlines 3) Tests/Quizzes/Study Guides 4) Problem Sets 5) ClassworkB

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AgendaAgendaDo Now (10)Quiz (20) Go over it (10) Notes (40) Puzzle Activity (40)

Quiz #7 (15 min max)Quiz #7 (15 min max)• No speaking • No looking left, right or up only on your paper. • It is timed. • Skip those you don’t get. • You can only use a blank periodic table and

pencil/pen. • No calculators needed.

2.2 Chemical Bonding2.2 Chemical Bonding

Lewis SymbolsLewis SymbolsValence e-s (VE) are involved in bonding Lewis symbols show VEs. One dot on each side,

then pair. Atoms lose (ionic), gain (ionic) or share

(covalent/molecular) to achieve stability (octet) rule).

We only include s and p orbitals because those are on the outermost level; “d” orbitals are lowest in energy

Why are d-orbitals not included?

Ionic Bonding Ionic Bonding • Ionic Bond – Bond formed through the transfer

of electrons. • Formed between a metal and a nonmetal.

Ionic Bonds Ionic Bonds Crystal Crystal Lattice Structures Lattice Structures

One ionic bond

Multiple bonds highly organized into a crystal lattice structure

When Na and Cl When Na and Cl form…form…

• They acquire charges • Opposite charges form what type of attractions?

• To satisfy what? • Do you see both ionization energy and e- affinity in this

process? • Forming ionic bonds release a lot of energy. This

energy is called enthalpy of formation (energy transferred during a rxn) symbolized by ΔHf

ΔHf = -350 KJ/mol

Exothermic = release

Lattice EnergyLattice Energy• A measure of how stable the crystal lattice structure is. • Lattice energy is the energy needed to completely

separate one mole of the crystal lattice structure into its gaseous ions.

Example 1: (disrupting ionic bonding) NaCl (s) Na+ (g) + Cl- (g) ΔH = + 788 KJ/mol

Energy NEEDED to disrupt this energy is called lattice energy.

Example 2: (formation of ionic bonds) Na+ (g) + Cl- (g) NaCl (s) ΔH = - 350 KJ/mol

Energy released to form crystals is also lattice energy

Coulombs LawCoulombs Law• Bigger the

charge, the __________ the attractive force.

• Larger the distance (or larger the atom is) then the __________ the attractive force.

Quickwrite: Quickwrite: Based on this data, how Based on this data, how

does it make sense with respect to does it make sense with respect to

Coulomb’s Law? Coulomb’s Law?

Then answer the question below:

Consider this:Consider this:• Lattice energy increases because charge increases,

and radii decreases. • But if charge increases, and radii decreases? Which is

more significant? • The charge is always more significant (or stronger)• What if the charges are the same, how do we

determine the difference in lattice energies between two different compounds with the same charge?

• Answer: Lattice energy depends on the distance and we use atomic radius from periodic trends to figure this out!

• The bigger the radius, the bigger the distance b/w the nuclei of two atoms , the LESS or MORE lattice energy to disrupt the bond?

Example 1:Example 1:• NaF and CsI are held by ionic bonds. Both have

the same charges +1 and -1. So according to Coulomb’s law, determine which would have the largest lattice energy.

• Step 1: Since charges are the same we need to see which has the smallest radius (distance) between the two atoms. That one will require lots more lattice energy.

• Step 2: Use the PT. Cs+ is larger than Na+ and I- is larger than F-. So, CsI has a larger distance between it’s nuclei meaning it’s easier to disrupt, meaning it would have a lower lattice energy.

Example 2: You tryExample 2: You try• Predict which of the following orderings of lattice

energy is correct for these ionic compounds. A) NaCl > MgO > CsI > ScN B) ScN > MgO > CsI > NaClC) NaCl > CsI > ScN > CaO D) MgO > NaCl > ScN > CsI E) None of the above are true

Justify below:

Example 2: You tryExample 2: You try• Predict which of the following orderings of lattice

energy is correct for these ionic compounds. A) NaCl > MgO > CsI > ScN B) ScN > MgO > CsI > NaClC) NaCl > CsI > ScN > CaO D) MgO > NaCl > ScN > CsI E) None of the above are true

Justify below:

ScN have +/- 3 charge so it has the highest lattice energy. MgO has +/- 2 charge so it has the next highest lattice energy

Both NaCl and CsI have +/- 1 charge so we determine lattice energy through size/atomic radii. CsI have larger atomic radius so larger distance b/w nuclei makes it easier to disrupt the structure, so CsI would require the least energy.

Answer is E

Puzzle ActivityPuzzle Activity• You are to preview Wednesday’s small lecture by

discovering PATTERNS

PURPOSE: You are to know the different between lone pairs and

nonbonding pairs Know how the octet rule applies to each puzzle piece Know how a single, double, or triple bond forms. What does the line represent. How do covalent compounds look like with bonds as

lines and lone pairs.

If done early, start on your HW.


① Which substance do you expect to have the greatest lattice energy: MgF2, CaF2, or ZrO2

② Justify your answer to #1. Hint: For ZrO2 you have to balance the charge since Zr is an transitional metal.

① Which substance do you expect to have the greatest lattice energy: MgF2, CaF2, or ZrO2

② Justify your answer to #1. Hint: For ZrO2 you have to balance the charge since Zr is an transitional metal.

Homework/Announcements: 1.Complete EVEN Problems from Problem Set 2.2

You were asked to complete Problem Set 2.1, please take those out. Incomplete HW will result in parent phone call.


Homework/Announcements: 1.Complete EVEN Problems from Problem Set 2.2

You were asked to complete Problem Set 2.1, please take those out. Incomplete HW will result in parent phone call.






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Catalyst ReponsesCatalyst Reponses

Puzzle ActivityPuzzle Activity• You are to preview Wednesday’s small lecture by

discovering PATTERNS

PURPOSE: You are to know the different between lone pairs and

nonbonding pairs Know how the octet rule applies to each puzzle piece Know how a single, double, or triple bond forms. What does the line represent. How do covalent compounds look like with bonds as

lines and lone pairs.

If done early, start on your HW.

DiscussionDiscussion: Based on the puzzle : Based on the puzzle activity, what main ideas did you activity, what main ideas did you discover about covalent bondingdiscover about covalent bonding::

Takeaways: Takeaways: Covalent Covalent Bonding (molecular Bonding (molecular

bonding)bonding) Atoms may acquire a noble gas electron

configuration by sharing electrons with others. This occurs between nonmetals. Remember,

hydrogen is a nonmetal. The sharing of two electrons results in one bond. Nonbonding electrons are called lone pairs. Bonded electrons are represented by lines. Single line (2 shared electrons) is a single bond. Two lines (4 shared electrons) is a double bond. Three lines (6 shared electrons) is a triple bond.

BoxBox the lone pairs, the lone pairs, circlecircle the bonding the bonding

electrons.electrons.

The “octet rule” for hydrogen is satisfied with ONE bond or two electrons. All other atoms should have 8 electrons on its exterior.. HYDROGEN should always have ONLY one line or two electrons!!!

Space filled models

Lewis Structures show lone pairs

Remember this:Remember this:

Hydrogen will never have a double or triple bond nor lone pairs

Oxygen typically has either a single or double bond, sometimes both.

Nitrogen likes to have triple bonds, but not always.

Quickwrite: What info Quickwrite: What info can be attained from can be attained from

this?this?Bond enthalpy – determines the strength of the covalent bond. Bond enthalpy is energy required to break a bond. Quickwrite:

bond length: the center-to-center distance between two bonded atoms

fairly constant for a given bond (ex: the C–H bond), no matter the compound

For example: C–H bonds in CH4 are about the same length as those in CH3CH2CH3

Bond Length: single bonds > double bonds > triple bonds (smallest)

Bond Strength: Triple bonds > double bonds > single bonds (weakest; and least energy stored)

C–C C=C C–C

1.54 Å

348 kJ/mol

1.34 Å

614 kJ/mol

1.20 Å

839 kJ/mol

Bond enthalpy:

1. Rank from smallest to largest bond 1. Rank from smallest to largest bond length. length.

2. Rank from smallest to largest bond 2. Rank from smallest to largest bond strength. strength.

Magic Spoon DemoMagic Spoon Demo

Covalent Bonding can be polar or nonpolar

When thinking about polarity, always think about electronegativity!

max. EN = 4.0 (F)

nonpolar covalent bond:

polar covalent bond:

electronegativity (EN): the ability of an atom in a molecule to attract e– to itself

Bond polarity describes the sharing of e–between atoms

e– shared equally

e– NOT shared equally

A bonded atom w/a large EN has a great ability to attract e–.

A bonded atom w/a small EN does not attract e– very well.

min. EN = 0.7 (Cs)

Dipole MomentsPolar covalent molecules have a partial (–) and a partial (+) charge and are said to have a dipole moment.

H–F H–F + –

partialcharge

O

HH

–

+ +

big EN = _____ polarity = _____ dipole momentbig big

Direction of higher electron density

Difference

VERY IMPORTANT: The EN for C-H bonds is so low they are considered nonpolar.

Polar molecules tend to align themselves with each other and with ions.

H–F H–F

H–F

H–F H–F

H–F NO3–

NO3– NH4

+

NH4+

Polar molecules like water, can dissolve ionic crystal lattice structures!

Polar covalent

ionic

They’re not ionic but polar and they attract because of this partial charge


Are the following polar covalent, nonpolar covalent, or ionic. 1.CH 2.HF3.NaCl

Are the following polar covalent, nonpolar covalent, or ionic. 1.CH 2.HF3.NaCl

Homework/Announcements: 1.Study old stuff, organize notes. 2.Quiz #8 on Lesson 2.1 and 2.2

Homework/Announcements: 1.Study old stuff, organize notes. 2.Quiz #8 on Lesson 2.1 and 2.2





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Draw the lewis dot structure for CN-Draw the lewis dot structure for CN-

Homework/Announcements: NoneHomework/Announcements: None





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Go To Class websiteGo To Class website• Mrnarez2015.wordpress.com• On announcements page, you will see a

googledoc link: click on it, and you will help create an annotated answer key.

1)For each wrong answer choice describe why it’s wrong. Check the work of others.

2) If you have a laptop please help place images into the googledoc. Use the word doc version of the worksheet on the second link on the class website home page.


Draw the lewis dot structure for

BCl3

HCNPCl5

Draw the lewis dot structure for

BCl3

HCNPCl5

Homework/Announcements: Outline Pg 317-321

Homework/Announcements: Outline Pg 317-321





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Today’s AgendaToday’s Agenda Quiz #8 Review Quiz Pogil Activity If time permits, Resonance Structures

Goals for today:Goals for today:1. Describe the role for the electron in each of

these bonds: ionic, covalent, and metallic

2. Identify the types of elements that would combine to form ionic, covalent, and metallic bonds.

3. Use EN values to identify the type of bonding b/w two atoms in a substance.

ap chem catalyst ap chem catalyst catalyst questions to do & homework ① based on what we...

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kjmol energy

ionization energy

lot of energy

lattice energies

ionic bonding ionic

enthalpy of formation

formation of ionic bonds

ionic bonding nacl s