Honors Chem Unit 4 Notes Covalent Bonding Fall '24 PDF

Happy Tuesday! 10/1 Find your new seats for the unit! Need at your desk: Start today’s Notebook bellwork on Chromebook Formative Notebook box Lab/Notes/Practice copies 10/1 10/2 1...

Happy Tuesday! 10/1 Find your new seats for the unit! Need at your desk: Start today’s Notebook bellwork on Chromebook Formative Notebook box Lab/Notes/Practice copies 10/1 10/2 10/3 10/4 10/7 10/8 10/9 10/10-11 10/14 Covalent Bonding Chemistry Unit 4  Intro to Compounds Lab  TYPES OF Ionic COMPOUNDS Covalent Organic Contain a metal and a Contain only nonmetals Subset of covalent nonmetal, or polyatomic Bonds formed from compounds (similar ions elements sharing properties) Bonds formed from ions valence electrons Primarily contain only H transferred between ○ Weak bond = low and C elements or ions melting point Often more complex than ○ Strong bond = high Generally insoluble in simple covalent melting point water molecules with higher Generally soluble in Poor conductors of molecular weights water electricity in solution Contain functional Produced ions in water A single unit of a groups ○ Good conductors of covalent compound is Have a variety of electricity in solution called a molecule different arrangements A single unit of an ionic called isomers that compound is called a create different formula unit properties for elements with the same formula  Sugar Salt C6H12O11 NaCl Lattice patterns are evident at all levels! Flavored sugar crystal are sold as ‘rock candy’ Under a microscope Actual sized crystals Under a microscope Actual sized crystals Sugar Salt C6H12O11 NaCl  C6H12O11 NaCl Melting Point: Melting Point: 366.8oF 1,474oF  Naming Covalent 1. Compounds first element Write the name of the __________________. a prefix 2. Add ______________ in front of the name to match the subscript. for ‘1’ a. EXCEPT if the first subscript is _________. Ex. Nitrogen monoxide NO (____) second element 3. Write the name of the ____________________ with the -ide ending. a prefix 4. Add ______________ in front of the name to match the subscript. Covalent 1 mono 3 Prefixes tri- 5 penta- 7 hepta- - 2 di- 4 tetra- 6 hexa- 8 octa- Writing Covalent Compound Formulas element symbol 1. Write the ______________ of the first part of the name. prefix 2. Add a subscripted number to match the _______________. 3. Repeat for the second part of the name. Shows the full/accurate Molecular Formula: ______________________ GLUCOSE count of elements in a molecule ________________________________ Shows the lowest whole Empirical Formula: ______________________ number ratio of elements in a molecule: ______________________________________ single unit of a covalent compound __________________________________  For tonight… Finish notes Spectrophotometry lab due tomorrow EdPuzzle (compounds due tomorrow) Covalent naming EdPuzzle due Friday Compounds practice due Thursday @ 8 AM  Happy Late Start! 10/2 Need at your desk: Start today’s Notebook bellwork on Chromebook Formative Notebook box (Properties & Coloring box Nomenclature) Notes/Practice papers Dot Diagrams Illustrates how valence electrons are distributed around free atoms, drawn as dots. Li Be B C N O F Ne Lewis Structures Illustrates how valence electrons are distributed around a molecule, Bonds are shown as lines Lone pair electrons, not shared between atoms, are dots  Cereal Modeling Lab Wash hands before you begin Continue working on notes/practice when finished with modeling  For Tonight… Complete any missing notes Covalent practice formative due tomorrow @ 8 AM Start studying for covalent quiz on Monday: ○ Naming & formula writing ○ Simple Lewis structures  Happy Thursday! 10/3 Need at your desk: Start today’s Notebook bellwork on Chromebook Formative Notebook box (Lewis Notes/Practice Structures) Drawing Lewis Structures 1. Determine the total number of valence electrons. 2. Draw a skeleton structure of the molecule or ion, arranging the atoms around a central atom. a. Place the least electronegative element in the center. b. Connect each atom to the central atom with a single bond 3. Distribute the remaining electrons as lone pairs on the terminal atoms (except hydrogen), completing an octet around each atom. Place all remaining electrons on the central atom. 4. Rearrange the electrons of the outer atoms to make multiple bonds with the central atom as necessary in order to obtain octets. More Info on Drawing Lewis Structures 1. Octet rule: Most elements bond to achieve a full valence shell of 8 electrons (except H and He) 2. Rules for ions a. Negative: Add the number of valence electrons equal to the charge on the ion b. Positive: Subtract valence electrons from the positive charge on the ion More Info on Drawing Lewis Structures 1. Formal Charge: The hypothetical charge the atom would have if we could redistribute the electrons in the bonds evenly between atoms a. The sum of formal charges must be zero for a molecule b. The sum of the formal charges in an ion must be equal to the overall charge of the ion 2. Resonance: If two or more Lewis structures with the same arrangement of atoms can be written, the actual distribution is an average of that shown by the various structure Resonance Structures Resonance structure are most favorable if: ○ A negative formal charge is on the most electronegative element. ○ Fewer elements have a non-zero formal charge Which Lewis structure is better, and why? Resonance & Formal Charge Practice CO32- CNO1- PO43- *most favorable resonant structure  Resonance Structures Molecules that demonstrate resonance are those that can be represented by multiple valid Lewis structures, typically containing at least one double bond (pi bond) and adjacent atoms with lone pairs, allowing for the delocalization of electrons across the molecule; common examples include ozone (O 3), nitrate ion (NO 3-), and benzene (C 6H 6). Lewis Structures Practice  For Tonight… Complete Lewis Structure Notes Khan Academys (4) due Tuesday Study for covalent quiz on Monday: ○ Covalent naming & formula writing ○ Simple Lewis structures  Happy Friday! Start today’s bellwork Need at your desk: on Formative Notebook (Resonance & Chromebook Formal Charge) Notebook box Coloring box  Valence shell electron pair _________________________________________________ repulsion VSEPR Theory theor _____________ y Lone pair - _________________ e- on a central shap atom have a significant impact on the ________ of e A B C D E a molecule linea A- r trigonal planar B- tetrahedral C- trigonal pyramidal D- bent E- Bond Polarity POLAR MOLECULES: Polar bonds, that are not cancelled out by symmetry, result in polar molecules. These molecules act like _____________ magnets & ________________________________________ interact with ions/other charged particles. Bond moment - shows the direction of electron pull in a bond Indicates the separation and direction of charge in a molecule POLAR (acting with a charge) COVALENT (composed of nonmetals) bonds result from an unequal sharing of electrons. 𝛅 - lowercase delta indicates partial charge  NONPOLAR MOLECULES: When electrons are ___________________ equally distributed they result in nonpolar molecules - even if being pulled away from central atom Br2I2N2Cl2H2O2 F2 Intermolecular forces (London) Dispersion Forces: A temporary charge on a molecule due to general electron movement. Occurs in ALL molecules. Cl2 Dipole-Dipole: A permanent charge on a molecule due to unequal sharing of electrons and dipole moments Hydrogen bonding: A very strong dipole that occurs when molecules have a H-F, VSEPR Modeling Lab This weekend… Complete notes on page 60 Naming/Formula/Lewis structures quiz Monday Khan Academy due Tuesday at 8 AM Make sure all assignments in your notebook are up to date!  Happy Monday! Need at your desk: Start today’s bellwork Notebook on Formative Chromebook (VSEPR) Coloring box  Covalent Compounds Quiz Continue working on your VSEPR Lab, Notes on pg. 60, or test corrections when finished  Tonight… Khan Academy due tomorrow at 8 AM Make sure all assignments in your notebook are up to date!  Happy Tuesday! Need at your desk: Start today’s bellwork Notebook on Formative Chromebook (ACT Practice) Coloring box Notebook box Polarity & IMF Practice Peardeck P PT  Tonight… Complete VSEPR Lab Test corrections due tomorrow Khan Academys due Monday (5)  Happy Late Start! Need at your desk: Start today’s Notebook bellwork on Chromebook Formative (Polarity & IMF)  Basic Hydrocarbon Nomenclature Naming molecules that contain onlycarbon __________ & hydrogen _______________. Number of carbons Types of bond in molecule 1- Meth - Single - -ane 2- Eth- Double - -ene 3- Prop- 4- But- Triple - -yne 5- Pent- 6- Hex- Other Types of Compounds Polymer - a large molecule made of a single unit that is ___________________________________________________________ repeated DNA, lipids, carbohydrates, plastic Ex. the unit that is repeated again and again in a polymer ____________________________________________________________ Plastics are examples of Monomer - polymers _____________ and are __________________________________________________________ named after their ______________. monomers The codes on the bottles do NOT indicate if they are are recyclable ______________. Hydrocarbons Lab Only create molecules that contain 1 double/triple bond, or a single functional group.  For Tonight… Khan Academys (5) due Monday at 8 AM Make sure your notebook is up to date  Cold particles move Energy slower than hot particles Thermal energy is kinetic energy associated with the random motion of atoms and molecules. Temperature is a quantitative measure of “hot” or “cold.” Heat (q) is the transfer of thermal energy between two bodies at different temperatures. Matter undergoing chemical reactions and physical changes can release or absorb heat. ○ Exothermic - a reaction or change that releases heat ○ Endothermic - a reaction or change that absorbs heat  Measures of Energy Simple A calorie (cal) is the amount of energy required to raise one Calorimeter gram of water by 1 degree C (1 kelvin). ○ A large calorie (C), is commonly used in quantifying food energy content, but is actually equal to a kilocalorie. A joule (J) is the amount of energy used when a force of 1 newton moves an object 1 meter. ○ 1 calorie = 4.184 joules.  Measures of Energy The heat capacity (C) of a body of matter is The specific heat capacity (c) of a the quantity of heat (q) it absorbs or releases substance, commonly called its “specific when it experiences a temperature change heat,” is the quantity of heat required to (ΔT) of 1 degree Celsius (or equivalently, 1 raise the temperature of 1 gram of a kelvin): substance by 1 degree Celsius (or 1 kelvin): Objects made of the same materials have the same specific heat. A larger pan would have a great heat capacity.  Enthalpy (Do not need to copy this slide) Enthalpy- sum of a system’s internal Thermodynamics - the relationships energy (U) and the mathematical product between heat, work, and other forms of of its pressure (P) and volume (V): energy in the context of chemical and ○ A state function - not path physical processes. dependent A negative enthalpy value represents an exothermic reaction. If the reaction takes place under constant pressure, the change in enthalpy is equal to heat of a reaction. A positive enthalpy value represents an endothermic reaction  Calorimetry Used to measure the amount of thermal energy transferred during a chemical or physical process. Specific heat must be written in units J/g*C  Bond Energy A bond’s strength describes how strongly each atom is joined to another atom and how much D = bond energy in kJ/mol energy is required to break the bond between the two atoms. As more bonds are formed between atoms, they become shorter and stronger. Energy must be added to break chemical bonds (an endothermic process) Forming chemical bonds releases energy (an exothermic process). Molecules are more stable if they have a higher bond energy Stop here in your notes! :)  Happy Monday! Needed at your desk Reminders Chromebook Notebook check/Unit Notebook 4 Test on Thursday Notebook box 10/17 Calculator Start today’s bellwork on Formative (Soda can calorimetry)  Soda Can Calorimetry Lab  Tonight Complete lab Reminders analysis Notebook Khan Academy check/Unit 4 (2) due Test on Wednesday Thursday 10/17  Happy Tuesday! Needed at your desk Reminders Chromebook Notebook check/Unit Notebook 4Test on Thursday 10/17 Calculator Start today’s bellwork on Formative Calorimetry How much heat must be added to a 8.21 g sample of gold to increase its temperature by 6.2 oC? q = mcΔT cAu = 0.13 J/goC  Calorimetry 15.0 g of CaCl2 is dissolved in 250 mL of water in a coffee cup calorimeter. The temperature of the solution increases from 25.2 oC to 35.7 oC. Calculate the enthalpy change for the dissolution of calcium chloride q = mcΔT cH2O = 4.184 J/goC  Calorimetry It requires 629 J of energy to heat a 50 g sample from room temperature, 22oC, to 49oC. What is the identity of the substance? q = mcΔT  Bond Energy Practice* Ethyl alcohol, CH3CH2OH, was one of the first organic chemicals deliberately synthesized by humans. It has many uses in industry, and it is the alcohol contained in alcoholic beverages. It can be obtained by the fermentation of sugar or synthesized by the hydration of ethylene in the following reaction. Calculate the enthalpy change for the reaction, ΔH. Breaking bonds = endothermic, Forming bonds = exothermic Independent Practice Intro to thermo calculations due by end of class tomorrow Khan Academy (2) - HW if not completed in class (Due Wed. by 8 AM) Complete Calorimetry Lab Make sure all notebook activities are complete  Tonight Enthalpy and Reminders calorimetry Notebook calculations check/Unit 4 (Submit on test on formative and Thursday show work in notebook)